Chapter II: Magnitudes of the Stars (4)

The reactions of water and of acids on many of the binary compounds are so important in determining the present composition of the earth’s crust that they must be considered in detail. The carbides, nitrides, chlorides, sulphides and hydrides of most elements, and some silicides, are decomposed by water, or else by dilute acids, forming the hydrogen compounds of carbon, nitrogen, chlorine, sulphur and silicon respectively, and the oxide or hydroxide of the other element. Thus calcium carbide and water give calcium hydroxide and acetylene, a hydro-carbon. Aluminum carbide yields alumina and methane (marsh gas), another hydro-carbon, the chief constituent of ‘natural gas.’ Other carbides yield crude petroleum. The nitrides yield ammonia, which is the hydrogen composed of nitrogen. The chlorides give hydrochloric acid, the sulphides sulphuretted hydrogen and the silicides the hydrogen silicide. The metallic hydrides yield free hydrogen.

The violence and the magnitude of some of these reactions almost baffle the imagination. Let the reader drop a piece of calcium carbide as large as a small marble into a little water in a cup; there is a rapid action, a gas (acetylene) is given off, which burns with a smoky flame if a lighted match is held over the cup. (The experiment should be tried in the open air.) So much heat is generated in the reaction that the cup becomes hot. Nearly four per cent. of the earth’s outer crust is calcium; all this was at this period of the earth’s history in the form of carbide. Imagine all the vast limestone mountain ranges of the present day as carbide, and try to realize the effect when water fell on any considerable area. The heat generated would be so enormous that in a moment the acetylene would ignite and burn, forming oxides of carbon and water vapor, which would in turn decompose, throwing the jets of glowing hydrogen and oxygen vast distances into the atmosphere, there to cool and reunite to water. The decomposition of other carbides, of the hydrides and silicides, as well as the formation of hydroxides by the action of the lighter metals on water, would produce similar phenomena, as the substances formed are combustible gases, or liquids or solids easily volatilized. This is no wild fantasy, but a conservative statement. Similar reactions are taking place at the present day in those stars whose cooling process has advanced far enough; a case in point is that of the so-called ‘temporary stars.’

Extremely violent reactions are taking place constantly in the atmosphere of the sun. The sun’s chromosphere, or outer layer of its atmosphere, consists mainly of hydrogen, and jets of glowing hydrogen are thrown to great heights above the chromosphere; these jets or ‘prominences’ have been frequently observed to have a height of 100,000 miles, and prominences of more than double this height are reported by observers. The most conservative estimates assume temperatures of the sun’s surface so enormous that that of the electric furnace is insignificant in comparison, and we can have no conception of the chemical changes occurring under such conditions. Whether one believes, with Lockyer, that the chemical ‘elements’ are disassociated by the sun’s heat into simpler substances or not, it is clear that very violent chemical reactions are in progress, and if we realize that the known chemical reactions increase in intensity with increase in temperature, it does not seem strange that at the sun’s temperature the reactions occurring should cause disturbances like those observed.

Returning to the earth, let us consider the products of these violent reactions. The hydrogen and hydrides of boron, silicon, sulphur and carbon, combined with the oxygen of the atmosphere, forming water and boric, silicic, sulphurous and carbonic acids, which in turn acted on the metallic oxides and hydroxides, forming sulphites, carbonates, borates and simple and complex silicates; some quickly, some slowly, some at low temperatures and atmospheric pressure, others at high temperatures in liquid or semi-liquid condition and under the pressure of rock masses above. To determine the relative age of existing rock layers, or the mode of their formation, whether by eruptive action, by surface heat, by deposition of finely divided material under water, or by metamorphic changes of the cooled silicate under subsequent action of water, pressure and heat, is the province of the geologist. The present writer refrains from an opinion whether any of the first formed solid crust could or could not survive to the present day in its primary form, considering the exposure to water, acids, heat and pressure which it suffered.

Yet an idea may be formed of the condition of the earth’s surface when it had cooled so far that the more violent chemical action had ceased. It consisted chiefly of silicates, simple and complex; of some of the original binary compounds, which are scarce affected by water or acids, such as the silicide of carbon (carborundum), of stable oxides, chlorides and sulphides, with other compounds in smaller proportion, and free elements in greater proportion than at the present day. Everywhere, from crevices in the surface, hydrocarbons, phosphoretted hydrogen (phosphine) and ammonia were issuing as gases; the atmosphere was heavy with these gases and with carbon dioxide.

No scientific observations thus far show _how_ or from what definite compounds plant life or animal life was first evolved from lifeless matter; but it is certain that the materials were much more abundant and the conditions more favorable at the period when it _was_ evolved than at the present day. An ocean much warmer and less saline than now, a damp atmosphere like that of a hothouse, an abundance of plant food and a choice of raw material, were at hand. The chief foods required for plant life are nitrogen in the form of ammonia or nitrates, carbon dioxide, phosphorus as phosphates, sulphates of lime, of magnesia and of the alkalies, and water. As to the raw material for the first formation of the living cell, it is impossible to say what compounds of carbon were employed; suffice it to note that the known simple and complex binary compounds of carbon were there ready for use; the hydrocarbons, carbon monoxide and carbon dioxide were oozing from the earth’s surface, from the ocean floor as well as from the land, or hanging heavy in the air above it. If warmth or increased pressure were desiderata, an ocean warm to its greatest depths could afford any pressure required. From the decomposition of the nitrides and phosphides below the surface, ammonia and phosphine were escaping into the ocean and into the air. The conditions then during long periods of time were especially favorable for marine life, and as sand and mud accumulated on the rocky surface of the earth, for land plants; the absence of a thick soil being more than compensated for by the abundance of plant food, notably of carbon dioxide and ammonia.

The statement may be found in excellent modern text-books of chemistry that ammonia is always formed by the decomposition of plants and animals, accompanied by the further statement that ammonia is a requisite for plant food. No plants--no ammonia; no ammonia--no plants. If this were true, the beginning of plant life would indeed have been a struggle for existence; that it is not true is shown above. This decomposition of nitrides has ceased practically on the actual surface of the earth at the present day because the nitrides have all been decomposed; yet it may be mentioned that specimens of rock freshly quarried in Sweden were recently found to give off ammonia when wet with water, showing the presence of nitrides. Below the actual earth’s surface it is probable that nitrides still exist in large quantity, for ammonia is one of the constituents of volcanic gases; to believe that volcanic ammonia is a product of plant or animal decomposition is difficult; to suppose it formed by the action of steam on nitrides in the earth’s interior is simple.

Much the same may be said of the presence of carbides. While they no longer exist on the surface, there is no doubt of their existence in the interior of the earth, and the volcanic gases contain their decomposition products. In this connection the theory--first put forward by Mendelèeff and since supported by Moissan--of the origin of petroleum, may be mentioned. These writers favor the hypothesis that it was formed by the decomposition of carbides by water under pressure; and while the evidence at hand perhaps favors the belief that the petroleum of the more important oil fields owes its origin to decomposition of the lower forms of marine animal life, yet there can be no doubt that petroleum may be formed by carbide decomposition, and it seems probable that natural gas is in part at least a result of the same action.

A PRELIMINARY ACCOUNT OF THE SOLAR ECLIPSE OF MAY 28, 1900, AS OBSERVED BY THE SMITHSONIAN EXPEDITION.

BY DR. S. P. LANGLEY,

SMITHSONIAN INSTITUTION.

Partly in deference to the report of the United States Weather Bureau, from which it appeared that the chance of a fair eastern sky on the morning of the eclipse was about 8 to 1, and after examination by Mr. Abbot of many stations in North Carolina, Wadesboro, of that State, was selected early in April as the site of the Smithsonian observations. The advantages of Wadesboro being also recognized by Professor Young, of Princeton, Professor Hale, of Yerkes Observatory, and the Rev. J. M. Bacon, of the British Astronomical Association, it came about that four large observing parties, besides several smaller ones and numerous excursionists from the surrounding country, were all joined to produce at Wadesboro one of the largest company of eclipse observers ever assembled for scientific purposes. It is a matter for congratulation that the sky at Wadesboro upon the day of the eclipse was cloudless and clearer than the average, so that the efforts of the observing forces were not thwarted by any circumstances beyond their control. The provisions of the Mayor and authorities of Wadesboro for preventing intrusion before and during the eclipse, and thus securing an undisturbed field of operations, deserve especial recognition. Further than this, the many acts of courtesy and hospitality to the visiting astronomers on the part of the townspeople will long be remembered by the recipients.

The Smithsonian party proper consisted of thirteen observers, and included Mr. Langley, Mr. Abbot, aid acting in charge of the Smithsonian astrophysical observatory; Mr. Smillie, in charge of photography; Mr. Putnam, of the United States Coast Survey; Mr. Fowle, Mr. Mendenhall, Mr. Child, Mr. Draper, Mr. Gill, Mr. Kramer and Mr. Smith. Included with these, the Rev. Father Searle and the Rev. Father Woodman gave most valuable assistance. Mr. Hoxie, of Port Royal, S. C., and Mr. Little, of Wadesboro, rendered valued assistance to Mr. Putnam during totality.

Professor Hale, of the Yerkes Observatory, was a member of the party, while still in general charge of the Yerkes expedition, and his counsel and aid were of the greatest service. Mr. Clayton, of Blue Hill Meteorological Station, occupied a part of the grounds of the Smithsonian party.

The main object of investigation was, of course, the corona, and of this, (first) a photographic and visual study of its structure; with, (second) a determination by the bolometer whether appreciable heat reaches us from it, and, if possible, an examination of the form of its spectrum energy curve.

The writer had been particularly struck, when observing the eclipse of 1878 on Pike’s Peak, by the remarkable definiteness of filamentary structure close to the sun’s limb, and had never found in any photographs, not even in the excellent ones of Campbell taken at the Indian eclipse of 1898, anything approaching what he saw in the few seconds which he was able to devote to visual observations at the height of fourteen thousand feet. His wish to examine this inner coronal region with a more powerful photographic telescope than any heretofore used upon it, was gratified by the most valued loan by Prof. E. C. Pickering of the new 12-inch achromatic lens of 135 feet focus, just obtained for the Harvard College Observatory. This lens, furnishing a focal image of more than 15 inches diameter, was mounted so as to give a horizontal beam from a cœlostat clock-driven mirror by Brashear, of 18 inches aperture, and used with 30-inch square plates. To supplement this great instrument, a 5-inch lens of 38-feet focus, loaned by Professor Young, was pointed directly at the sun. This formed images upon 11 × 14 plates moved in the focus of the lens by a water clock. Specially equatorially mounted lenses of 6, 4 and 3-inch aperture, driven by clock work, were provided for the study of the outer corona, and the search for possible intra-mercurial planets.

For the bolometric work, the massive siderostat with its 17-inch mirror, and a large part of the delicate adjuncts employed at the Smithsonian Institution in recent years, to investigate the sun’s spectrum, was transported to Wadesboro. The excessively sensitive galvanometer reached camp without injury even to its suspending fibre, a thread of quartz crystal 1-15,000 inch in diameter.

Besides these two chief aims (the photography and bolometry of the inner corona), several other pieces of work were undertaken, including the automatic reproduction of the ‘flash spectrum’ by means of an objective prism with the 135-foot lens, the photographic study of the outer coronal region, including provision for recognizing possible intra-mercurial planets, already alluded to, visual and photographic observations of times of contact, and sketches of the corona, both from telescopic and naked-eye observations.

The assignment of the observers was as follows: Mr. Langley, in general charge of the expedition, observed with the same 5-inch telescope used by him on Pike’s Peak in 1878, which was most kindly lent for this special comparison by Professor Brown, of the United States Naval Observatory; C. G. Abbot, aid acting in immediate charge, assigned with C. E. Mendenhall to the bolometer; T. W. Smillie, having general direction of the photographic work, made exposures at the 135-foot telescope; F. E. Fowle, Jr., assigned to the 38-foot telescope; Father Searle, directing the assembled telescopes for the outer coronal region, and for intra-mercurial planets, assisted by P. A. Draper and C. W. B. Smith, exposed two cameras of 3-inch aperture and 11 feet focus, and two of 4½-inch aperture and 3½ feet focus, all four of these telescopes being mounted on a single polar axis driven by an excellent clock; De Lancey Gill, assisting Mr. Smillie, removed the flash spectrum objective prism at second contact, and made a single long exposure with a 6-inch photographic lens of 7½ feet focus equatorially mounted; Assistant G. R. Putnam, who, by the kindness of the superintendent of the United States Coast Survey, was detailed for latitude,[C] longitude[D] and time observations, also observed contacts, directed the striking of signals by Mr. Little, and rendered other valuable services. Mr. Putnam was assisted in recording contacts by Mr. Hoxie. R. C. Child, observing with a 6-inch telescope of 7½ feet focus, made sketches with special reference to inner coronal detail, and was in addition charged with all electrical circuits for chronograph and automatic photographic apparatus. Father Woodman, with 3½-inch telescope, observed contacts and made sketches.

[C] 34°, 57′, 52″ N.

[D] 5h., 20m., 17.8s. W.

The first detachment, consisting of Messrs. Abbot, Fowle, Kramer (instrument maker) and Smith (carpenter), reached Wadesboro May 4th, and were soon joined by Messrs. Draper and Putnam. The latter returned to Washington after a short but satisfactory latitude and longitude campaign, reaching Wadesboro again just before the eclipse. Other members of the party reached camp on and after the middle of the month. The first comers found a very satisfactory shed already erected and piers begun. Not a day passed from the time of the arrival of the apparatus, May 7th, to the day before the eclipse, that was not fully occupied in perfecting the arrangements.

The most striking portion of the installation was the line beginning at the northwest pier, with its equatorial and cœlostat, continued from thence south of east by the two great diverging tubes of the 135-foot telescope and spectroscope. These tubes were covered with white canvas, presenting the appearance of two immensely prolonged ‘A’ tents, ending beyond the photographic house, where the 38-foot telescope tube pointed east and upward at an angle of 42° with the horizon. When the equatorial, with its large special conical tube camera, with all this long-branching extent of white canvas ending in the uplifted tube of the 38-foot telescope, was seen in the light of the moon, the extensive field with these preparations, exhibited a still more picturesque scene than by day.

Less imposing, and perhaps more ungainly was the combination of four great cameras under the main shed, designed to search for new planets and to depict the outer corona. These might well be described as like a cabin and outbuilding, mounted on a polar axis, yet, despite their awkward proportions, they were made to follow very accurately.

The morning of the eclipse dawned cloudless and very fairly clear. Deep blue sky, such as the writer had seen on Pike’s Peak, of course, is not among the ordinary possibilities of an eclipse, but the milkiness of the blue was less pronounced than is usual in the summer season, and all felt that the seeing promised well.

At fifteen minutes before totality a series of rapid strokes on the bell called every one to his post, and one minute before the expected contact five strokes were given as a final warning. Coincidentally with the actual observation of the second contact by Mr. Putnam, the first two strokes upon the bell sounded, and the work began. After 82 seconds (the duration of totality from the Nautical Almanac was 92 seconds), three strokes were given as a signal to stop the long photographic exposures. Scarcely more than five seconds after this the sun’s crescent reappeared. The duration of totality, as observed by Mr. Putnam, was approximately 88 seconds.

To visual observers the sky was notably not a dark one. No second magnitude stars were observed with the naked eye, and most of the on-lookers saw only Mercury conspicuously, though Venus was distinguished at a low altitude and Capella also was seen. So high a degree of sky illumination can not but have operated unfavorably in the study of the outer corona or in the search for intra-mercurial planets, and this is to be remembered in connection with what follows.

BEFORE TOTALITY.

A deepened color in the sky, a fall of temperature and a rising breeze were distinctly noticeable. No change in direction of the wind was noted. Shadow bands were seen, but those who attempted to measure their velocity found them too rapid and flickering for any great exactness in this determination. There was tolerable unanimity among independent observers as to their size and distance apart (about five inches), though some thought this less as totality approached.

It was noticed that the birds grew silent just before and during totality, but true to their nature, the English sparrows were last to be still and first to begin their discussion of the eclipse, after the return of light.

DURING TOTALITY.

The attention of all visual observers was at once caught by the equatorial streamers. Father Woodman’s comparison of the appearance of a structure of mother of pearl was generally recognized as good, but different observers differed on the color estimate. A yellowish green tinge was noted by the artist of the party, Mr. Child, while to others the light was straw colored or golden.

The general coronal form to the naked eye was nearly that of the small annexed photograph, which, though taken by one of the smaller objectives, gives a good view of the relative intensities. The same extensions of the equatorial corona could be followed by the naked eye from 3 to 3½ solar diameters.

The visual telescopic observations of the writer gave little indication of the finely divided structure of the inner corona which he had noticed at Pike’s Peak. Structure, to be sure, was evident, but not in such minute subdivision as had then been seen, and though one remarkable prominence as well as several smaller ones was visible, the coronal streamers did not give to the writer the impression of being connected with these prominences, though the relationship of some of them to the solar poles was abundantly manifest.

AFTER TOTALITY. _Results._

Comparing notes after totality, all observers reported a successful carrying out of the programme. The greatest interest centers in the direct coronal negatives taken with the 135-foot telescope. Mr. Smillie exposed six 30 × 30 plates during totality, with times ranging from one half a second to sixteen seconds, and three others were exposed by him immediately after the third contact.

At this writing only a part of the negatives taken have been developed. Their general quality may be inferred from the examples here given, after due allowance for the great loss suffered by translation onto paper even with the best care.

Fig. 1 is a view taken with one of the smaller objectives (6 inches), given here to afford the reader an idea of the general disposition of the coronal light. The upper part is the vertex in the inverted field.

Fig. 2 is a portion of one of the great 15-inch circular images obtained with the 135-foot focus telescope. It was obtained in the great disc in the last exposure during totality of 8 seconds, showing one of the principal prominences then on the sun’s disc, with the disposition of the lower filaments near it.

Fig. 3 is a portion of one of the same set of plates, but taken with a 16-second exposure. The part near the sun has, of course, been intentionally over-exposed, in order to better exhibit the remarkable polar streamers, extending here to a distance of about six minutes from the sun, but seen still further in Mr. Child’s telescopic drawing (not given.)

Fig. 4 is a view of a small part of the great apparatus on the field, including the terminus of the horizontal tube with its canvas covering, which has been described as like an extended ‘A’ tent. The photographic room is seen at the end of the tube, and beyond that the tube containing the lens loaned by Professor Young pointing directly skyward.

That it will be impracticable to give here all of the disc of the moon in the large photographs, will be evident when it is considered that the lunar circumference on each plate is about 4 feet; but it will be inferred from the examples that the prominences and polar streamers as well as their features, appear in imposing magnitude and detail.

Many of what it is hoped will be the most interesting photographs still await development, but Mr. Smillie’s thorough preparation is promising adequate results.

HEAT OF THE CORONA.

Mr. Abbot, with aid of Mr. Mendenhall, appears to have measured the heat of the corona, and in spite of previous efforts, this is probably the first time that it has been really shown to exist. For five minutes before second contact, the bolometer was successfully exposed to the region of the sky close to the narrowing crescent of the sun where the corona was shortly to appear. A diaphragm was interposed in the beam having an aperture of only 0.4 sq. cm. Deflections, rapidly diminishing from 80 to 6 mm. were obtained, the last being about 40 seconds before totality. Then the diaphragm was opened to 290 sq. cm. and a negative deflection of 13 mm. was observed after totality, where these positive deflections had just been found, showing that the corona was actually cooler than the background which had been used at the room temperature. Next the black surface of the moon was allowed to radiate upon the bolometer, and the still larger negative deflection of 18 mm. was observed.

The important result was that the corona gave a positive indication of heat as compared with the moon.

This heat, though certain, was, however, too slight to be sub-divided by the dispersion of the prism with the means at hand.

The negatives taken to depict the outer corona show from three to four solar diameters extension for the longest streamers. The equatorial ‘wings,’ as they recede from the sun, are finally lost in an illuminated sky, without any indication of having actually come to an end.

No attempt to carefully examine the plates taken for intra-mercurial planets has yet been possible. It is, however, as has been remarked, doubtful if the very faintest objects will be found, in consideration of the considerable sky illumination during totality. However, Pleione in the Pleiades (a star of the 6.3 magnitude), is plainly seen on one of the plates, and some smaller ones are discernible.

On the whole, the expedition may be considered as promising to be very satisfactory in its results, and that it was so is largely owing not only to the efficient care of Mr. Abbot, but to the many gentlemen who have assisted me with the loan of valuable apparatus, with counsel, with voluntary service and with painstaking observation, to one and all of whom I desire to express my obligations.

MALARIA AND THE MALARIAL PARASITE.[E]

BY PATRICK MANSON, M. D., LL. D.,

LECTURER ON TROPICAL DISEASES AT ST. GEORGE’S HOSPITAL AND CHARING-CROSS HOSPITAL MEDICAL SCHOOLS AND AT THE LONDON SCHOOL OF TROPICAL MEDICINE.

[E] Abstract of a lecture delivered at the Medical Graduates’
College and Polyclinic, and printed in the _Lancet_ of May 19.

This lecture is devoted to a description of the parasite and of its life cycles. The existence of a parasite in malarial disease has been suspected for a long time, but only very recently have we had absolute assurance that such a parasite exists. Some time in the thirties Meckel described in the human blood certain black particles which he found in leucocytes and in certain pale, leucocyte-like bodies the nature of which he did not know. When he saw these bodies he certainly saw the malarial parasite. His observations were repeated and extended in the forties and the fifties by Frerichs and Virchow, and they, too, undoubtedly saw the malarial parasite. But it is one thing to see and quite another to recognize; discovery is recognition.

The discoveries of Laveran, Golgi, Marchiafava, Bignami and others resulted in considerable knowledge of the life history of the malarial parasite and of the correspondence between its life cycle and the clinical cycle of the disease. Laveran discovered the parasite; Golgi described the cycle of the tertian and quartan forms; the others added new data, especially concerning the more malignant parasites. The malarial parasite in its mature form has the appearance--I shall take the tertian parasite as a type--of a mass of pale protoplasm occupying practically the whole of the red blood corpuscles. Scattered through this mass of protoplasm are a number of black specks or little rods of intensely black pigment. Later in the life of the parasite a peculiar thing happens: all these little specks of black pigment concentrate usually towards the center of the organism whilst the pale protoplasm arranges itself into little spherules, the whole constituting what is known as the ‘rosette body.’ Later in the life of the parasite the surrounding blood corpuscle breaks away and this rosette body floats free in the liquor sanguinis and then breaks up into its constituent spores, setting free at the same time the black pigment clump. Phagocytes attack many of these free spores and probably absorb most of them, as well as the little pieces of pigment. The result is the pigmented leucocyte, so characteristic of malarial blood. A few of the spores escape and in virtue of some peculiar faculty, which is not at present understood, enter fresh blood corpuscles and appear there as pale specks in the hæmoglobin. These pale specks, if watched in perfectly fresh blood, are seen to be possessed of very active amœboid movement. They throw out pseudopodia in various directions and wander about through the hæmoglobin of the corpuscle. After a time they increase in size by assimilating the hæmoglobin. By and by there appear somewhere in the parasite those specks of black pigment which we saw in the mature animal. Later they increase still further in size until they come to occupy half, and finally nearly the whole, of the blood corpuscle. Again there is concentration of pigment and the formation of little sporules. This is the cycle, as described by Golgi, of the tertian and quartan parasite. The cycle of the tropical or æstivo-autumnal parasite corresponds in plan almost exactly with that of the quartan and ordinary tertian parasite.

It was found that the life cycles of these parasites ran parallel with the clinical cycle of malarial disease. It was found that when the parasite had arrived at maturity the apyretic interval in an ague was about to conclude, and that when the parasite had arrived at the sporulating stage the patient had entered on the shivering stage of his fever. During that and the succeeding hot and sweating stage the spores had entered the red blood corpuscles, and when the parasite had ensconced itself in the red blood corpuscle and begun to grow, the fever had come to an end. It was found in tertian fever that the cycle of the parasite took forty-eight hours to complete, exactly the length of the cycle of the clinical phenomena. In quartan fever the cycle took seventy-two hours, exactly the length of the clinical cycle of that form of malarial disease. In the malignant or tropical fevers there was found to be a similar correspondence between the cycle of the parasite and the cycle of the disease. It was found that with each recurring paroxysm of fever there was a renewal of the life of the parasite, and that in this way the life of the parasite was continued from period to period and from cycle to cycle for weeks or even, especially in the case of quartan malaria, for months. Now this explains very well the way in which the malaria parasite contrives to maintain its existence in the human body, but it does not explain how it passes from host to host, neither does it explain certain appearances that Laveran and everybody else who has studied the subject have witnessed. In malarial blood you sometimes see that peculiar body, the flagellated body, which I have already alluded to as consisting of a sphere surrounded by from one to six or seven long tentacles or arms in a state of continual agitation. Neither does it explain the peculiar crescent-shaped body which also so pointedly arrested Laveran’s attention.... Golgi’s scheme leaves the passage of the parasite from host to host and also the nature of these two bodies unexplained. What relation have these two bodies to the life of the parasite? Their nature and purpose do not receive any illumination from Golgi’s theory. You will find in all forms of malarial infection, if you look enough, the flagellated body; but, strange to say, you will not find it in malarial blood immediately after it is withdrawn from the body. It is only after an interval of minutes, perhaps a quarter of an hour, after the blood is withdrawn that these flagellated bodies appear. Whence do they come? If you make a preparation of malarial blood from a patient by pricking the finger and spreading a little of the blood on a slide, fixing it immediately with heat or alcohol and staining it, you will never see any of these flagellated organisms. But if the slip be kept moist and in a warm temperature for half an hour and then stained, the flagellated bodies will be seen, proving that they develop only after the escape of the parasite from the human body. Such a fact is very interesting and obviously has some significance in connection with the life of the parasite. Whence, I ask, come these flagellated bodies? If one of the crescent-shaped bodies is observed continuously, the following changes of shape may often be observed: It becomes shorter, loses its crescent shape and gives off flagella, which may break off and swim about by themselves. When they come in contact with a blood corpuscle they straighten themselves out and indulge in a peculiar vibratory movement, as if endeavoring to penetrate the corpuscle.

Many years ago King, in America, and others too numerous to mention suspected that the mosquito had something to do with malaria, but in what way they could not say. Not only civilized observers had this suspicion, but the savage natives of certain tropical countries had the same idea. Koch tells us that certain natives of German East Africa who lived in a mountainous, and therefore non-malarial, part noticed that when they descended to the malarial regions on the coast they acquired a fever which they called ‘mbu.’ They said that they were bitten there by certain insects which they also called ‘mbu’--mosquito or gnat. They give the same name to the mosquito and to the fever, therefore obviously these savages associate the insect and the fever as cause and effect. Peasants in certain parts of Italy have the same idea, believing that the bite of the mosquito may be followed by the development of malarial fever.

Laveran, some years ago, in one of his numerous works on malarial fever, said that possibly the malarial parasite was cared for by the mosquito in the same way that the latter cares for the filaria of the blood. He did not, however, formulate a definite theory on the subject.

In 1894 I was engaged in working at malaria, following out Golgi’s work and that of other Italians. I was particularly struck by the phenomena of exflagellation and more particularly by the fact that it occurred only when the blood had been removed from and was outside the human body. I reasoned that if this exflagellation occurs only outside the body, the purpose of the flagellated body must lie outside the human body, and that therefore the flagellated body must be the first phase of the malarial parasite outside the body, must be the first step that the malarial parasite takes in passing from one human host to another. There seemed to me to be a sort of logic in this. But how was the malarial parasite to pass from one human being to another? It was not provided while inside the human body with any organs of locomotion or penetration; as far as we know the parasite is never extruded in the excreta, neither does it habitually escape in hæmorrhages. Therefore, the idea of a spontaneous escape of the parasite from the human body had to be dismissed. I therefore concluded that some extraneous agency must remove the parasite from the human body, so as to afford the opportunity for this flagellation which I had concluded must constitute the first step in its extra-corporeal life. In casting about for an organism which could effect this removal I, for many reasons similar in some respects to those that influenced the savage African, the Italian peasant, King, Laveran and others, came to the conclusion that the medium of removal and transit must be the mosquito. I was so impressed with the probabilities of this double hypothesis and with its extreme practical value, should it prove to be correct, that I endeavored to leave England for a time and to visit British Guiana or some such suitable malarial country where I might work out the idea. Unfortunately, that could not be accomplished, so I published my theory in the hope that it would appeal to someone who might enjoy the opportunities denied to me. At that time Surgeon-Major Ross was at home from India and we had many conversations on the subject. I described to him my hypothesis, the probabilities of which and the possibilities of which powerfully appealed to his highly logical and practical mind. He undertook, when he returned to India, to do his best either to establish or confute it. Accordingly he set to work in India experimenting with mosquitoes and malaria.

Ross was stationed in Secunderabad, in the south of India, where there was abundant opportunity for experimental work--plenty of patients and plenty of mosquitoes. He got patients with crescent parasites in their blood and he got mosquitoes to bite them. He found that in the course of a few minutes after the blood had entered the insects’ stomachs the crescent parasites proceeded to the formation of sphere and flagellated body. But he got no further. This experiment was repeated hundreds of times. Many of his preparations were sent to me, and I could confirm from them the accuracy of his statements on the subject. Ross was encouraged, for obviously we were on the right track. One day Ross, whose station had in the meantime been changed, caught some mosquitoes which had been feeding on a patient the subject of tertian malaria. He kept the mosquitoes and after a few days dissected them. He took the stomach out and placed it on a slip with a little salt solution, covered it with a cover-glass and examined it with a microscope. He was gratified to find lying amongst the transverse and longitudinal muscular fibres a number of spherical bodies, very sharply defined, and including a great many grains of intensely black pigment exactly like those of the malaria parasite. Ross was at once struck with the similarity. After years of labor he believed he had at last seen the malaria parasite in the tissues of the mosquito, where we reasoned it ought to be; and he was right. At a subsequent experiment on the malarial patient he found exactly the same bodies, and on dissecting several mosquitoes at different intervals of time he found that the parasite, which originally was six micro-millimetres in diameter only, grew to sixty or eighty micro-millimetres, each parasite, notwithstanding its growth and the lapse of time, still containing the peculiar and most characteristic black pigment. Ross was now quite sure that he had found the extra-corporeal phase of the malarial parasite. Some of these preparations he sent home. I examined them and showed them to a number of friends in London familiar with the malarial parasite; they agreed with me, as Laveran also did, in believing that probably this indeed was the long-sought-for extra-corporeal phase of the malarial parasite. Ross at that time had great difficulty in getting opportunities for experiment on the human subject and in procuring proper mosquitoes. He found that the mosquitoes in which he had discovered these pigmented bodies were of a different species to those on which he had formerly experimented, and that in this circumstance lay the explanation of his lack of success earlier as well as the secret of his ultimate success. Failing to get sufficient opportunity for experimenting on human malaria he turned to bird malaria. He found that the sparrow of Calcutta, in a large proportion of instances, contained in its blood a malaria-like parasite. Ross procured a number of infected sparrows and let loose upon them a number of mosquitoes of a species belonging to the genus _culex_. These mosquitoes, after from one to ten days, he dissected and examined their stomachs. He found in the stomach-wall pigmented bodies exactly similar to those which he found in the stomach-walls of mosquitoes fed on human malarial blood. He found that they increased in size and in a week or ten days grew from six to eighty micro-millimetres in diameter. When they became of considerable size they protruded like warts from the surface of the insect’s stomach and were included in a very definite capsule. At this stage the capsule was filled with a vast number of very minute rod-like bodies. These capsules, which now projected into the body cavity of the insect, being over-distended, ruptured and discharged the rod-like bodies into the body cavity of the mosquito. For a time Ross could get no further than this. He could not find what became of the rod-like bodies. One day, in dissecting the head of a mosquito, he encountered two small trilobed glands the ducts from which united to form a main duct. The glands lay on either side of the head and the common duct he traced to the base of the proboscis of the mosquito. This was the salivary gland of the mosquito. He found that the cells of the gland contained rod-like bodies exactly like those which he had found inside the parasitic capsules in the stomach-wall. He concluded that somehow these ‘germinal rods’ (for so he called them) had managed to find their way into the salivary gland of the mosquito. It immediately occurred to him that this might be the route by which the parasite escaped from the mosquito into its vertebrate host. No sooner had the idea occurred to Ross than he put it to the test of experiment. He selected a number of sparrows in whose blood he satisfied himself that there were no parasites and let loose upon them a number of mosquitoes which he had already infected with malarial parasites. He found after a week or ten days that the sparrows which were experimented upon sickened and many of them died; and in their blood he found the malarial parasite.

We now understand why the flagellated body is developed outside the human host: because its function lies outside the human host. We now understand why the flagella break away and enter the granular sphere: they impregnate it and start it on the road of development. We now understand why MacCallum’s vermicule is beaked and endowed with powers of locomotion and penetration: that it may approach and penetrate the stomach of the mosquito. And we now know why the sporozooites, the ‘germinal rods,’ enter the mosquito’s salivary gland: that they may be injected into vertebrate issue and so pass the parasite from vertebrate to vertebrate.

This is one of those fairy tales of science which people are inclined to doubt, but any one who has worked at the subject and taken the trouble to go through the long series of preparations which have been sent home from India can not for a moment have the slightest doubt that what Ross stated was absolutely true, and that not only for bird but for human malaria. So soon as the idea got abroad that the key to the way in which the malarial parasite is propagated had been found the Italians immediately set to work with renewed vigor and with the utmost skill. Almost at once they demonstrated that what happened in the case of Ross’s sparrows happened also with the human subject: that the appropriate species of mosquito fed upon the human malarial subject and subsequently allowed to feed upon a non-malarial subject conveyed the malarial parasite and malarial disease, and that the appropriate species of mosquito belonged to the genus anopheles. There can not be the slightest doubt that the mosquito acts the part of transmitting agent as well as definitive host of the malarial parasite.

This is a piece of knowledge of the utmost importance to mankind, for we know that malarial disease in tropical countries--which, after all, in the future will be the most important parts of the world, seeing that they can produce more food than temperate countries and can therefore support a larger population--causes more deaths and more disposition to death by inducing cachectic states predisposing to other affections than all the other parasites affecting mankind put together. We know now in what way this parasite is acquired. Depend upon it, in time, in virtue of this knowledge, we will get enormous power over the disease and sooner or later we will be able to prevent the infection of man by the parasite. It is only a question of study and the application of the knowledge already acquired, only a question of money and perseverance and a little ingenuity, and these results will come. It may not be in ten years or twenty years, but sooner or later the energies of a considerable portion of scientific mankind now being expended in endeavoring to devise means for preventing the infection of men with the malarial germ by the mosquito will bear valuable fruit.

You can readily understand that it is of great importance to be able to recognize the special species of mosquito which convey malaria. The effective species as regards human malaria belong to the genus anopheles; species of the genus culex are effective in the case of sparrow malaria. Fortunately, these two genera are easily recognized even by the amateur zoölogist. If you find a mosquito clinging to the wall or other surface you can tell which genus it belongs to by its posture. If the body is stuck out nearly at right angles to the surface on which the insect is resting, it is an anopheles. If the body is almost parallel to the surface, it is a culex. There is another test which is easily applied if you have a pocket lens; in culex the two organs known as palpi are rudimentary and very short; whereas in anopheles those organs are almost as long as the proboscis. It should be remembered that the male mosquito is not a blood-sucker and therefore is not dangerous. It is the female anopheles which transmits the disease. The mosquito larvæ inhabit stagnant or slow-running water. If a mosquito larva be found with its head downwards, the body hanging at right angles to the surface of the water, it is a culex; if the body lies parallel to the surface of the water, it is an anopheles. There are other points of difference with which I need not now trouble you; those referred to suffice for diagnosis between the innocuous and the dangerous mosquitoes.

The facts regarding the malaria parasite which I have described are of great importance for many reasons. First, because they help us to understand the pathology and etiology of malaria. Secondly, they help us in diagnosis. Thirdly, our knowledge of the parasite is invaluable in directing treatment. Lastly, a knowledge of the life-history of the malarial parasite is of extreme value for the prevention of malarial disease, for could we by mechanical or other arrangements prevent the mosquito attacking the human body, we could prevent the malarial parasites from entering the human body; or if we could abolish the mosquito by drainage or other means from a country, then we might be sure that we would abolish the malaria of that country also.

Attempts are being made to solve these practical problems. At the present moment such attempts are being actively made in Rome by Professor Celli and elsewhere by others. I have no doubt that in the course of a few years we shall get some very valuable results in this direction and that, thanks to this new-born knowledge about the malarial parasites, better times are rapidly approaching for malarial countries.

NEW SOURCES OF LIGHT AND OF RÖNTGEN RAYS.

BY HENRY CARRINGTON BOLTON, PH. D.

Among the general laws of physical science, none seems more firmly established than that of the conservation and correlation of energy; according to this the various forms of energy that constitute the domain of experimental physics, heat, light, electricity, magnetism and chemical action, have reciprocal dependence and “can not originate otherwise than by devolution from some preëxisting force,” or rather energy. That motion is convertible into heat, heat into light and both the former into electricity are phenomena familiar to every one who uses incandescent bulbs or rides in a trolley, and we do not usually recognize any production of light unaccompanied by heat. True, the little fire-fly is possessed of a mysterious power that enables it to emit light without enough heat to affect Langley’s most sensitive bolometer, but the eminent Secretary of the Smithsonian has to admit that the “cheapest form of light” is produced by “processes of nature of which we know nothing.” This little understood property called phosphorescence is shared by many living organisms, both animal and vegetable, as well as by substances of the mineral kingdom; to the former belong coelenterates, mollusks, crustacea, fishes and insects, and decaying wood, certain mushrooms, etc.; to the latter the Bologna stone, so-called, and the commercial article called ‘Balmain’s paint.’

In the case of the mineral substances, barium or calcium sulfids and the like, the light-giving power is not an innate property, but is set in operation by exposure to the energy of sunlight, the light of burning magnesium or to some other source of actinism; moreover, the power thus acquired by insolation is a fugitive one, the substances exercising it after three or four hours become ‘dead’ and lose their activity. Excepting then these living beings and these phosphorescent bodies, light as commonly known to us is always correlated with heat; within the last four years, however, discoveries have been made in France that seem to modify the position taken by philosophers and to necessitate new views concerning the manifestations of that energy with which the universe is endowed. A group of French savants have found mineral substances that apparently give out light perpetually without any exciting cause, realizing the dream of the alchemists--a perpetual lamp consuming no oil. These substances also emit rays having the penetrating properties of X-rays, other rays affecting a photographic plate, and fourthly, rays causing air to become a conductor of electricity. The history of these discoveries can be briefly given.

Röntgen’s discovery of the rays that pass through metals and solids opaque to light was made in 1895, and in the following year, Becquerel, a distinguished French academician, discovered that salts of the metal uranium (substances that had long been used in coloring china and glass) emit invisible radiations capable of discharging electrified bodies and of producing skiagraphic images on sensitive plates; he found that potassio-uranic sulfate emits rays that pass through black paper and give photographic impressions in the same way as Röntgen rays. This property is not limited to the brilliantly fluorescent uranic salts, but is shared by the non-fluorescent uranous salts, and is exhibited by compounds whether phosphorescent or not, whether crystalline, melted or in solution, as well as by the metal itself. The permanence of this activity is amazing, substances kept in a double leaden box more than three years continuing to exert the power.

Shortly after the announcement by Becquerel, experimenters found that other substances have the power of emitting ‘Becquerel Rays,’ such as calcium and zinc sulfids and compounds of thorium. In 1898 Mme. Sklodowska Curie, working in the laboratory of the Municipal School of Industrial Physics and Chemistry in Paris, devised a special apparatus for measuring the electrical conductivity of the air when under the influence of ‘radio-active bodies,’ and by its means studied the behavior of pitchblende (uraninite), and of other uranium minerals; finding that some specimens of pitchblende had three times as much energy as uranium itself, she came to the conclusion that the peculiar property is due to some unknown body contained in the minerals and not to uranium. Examining the mineral with the aid of her husband, the two found a substance analogous to bismuth, four thousand times stronger than uranium, which was named ‘Polonium,’ in honor of the native land of Mme. Curie. In December of the same year, the lady received the Gegner prize of 4,000 francs awarded by the Academy of Sciences, as a substantial appreciation of her discovery, and later in the same month Mme. and M. Curie announced that they had found a second body in pitchblende, which they named ‘Radium.’ More recently, M. Debierne, working under the auspices of Mme. Curie, has discovered a third body, which he calls ‘Actinium,’ an unfortunate appellation because ‘actinium’ has already been used for an element announced by Dr. Phipson and since discarded.

These three ‘radio-active’ substances do not possess identical properties; their rays are unequally absorbed and are differently affected in a magnetic field; moreover radium emits visible rays, while polonium does not. Nor have they the same chemical affinities; polonium belongs to the bismuth group, radium to the barium and actinium to the titanium series. They have not been separated perfectly from their analogues, and consequently their chemical properties and the actual intensity of their physical activities is very imperfectly known. The difficulties of securing even small quantities of crude materials are enormous; Fritz Giesel obtained from one thousand kilograms of raw material only fifteen grams of active compounds, and Mme. Curie, operating on half a ton of the residues of uranium from a chemical manufactory, got about two kilograms of barium chloride rich in radium, but the percentage of active substances in these mixtures is unknown.

Radium is spontaneously luminous, and all the bodies emit rays that excite phosphorescence in gems, fluorite and other minerals; they communicate radiant energy to inactive substances, and they exert chemical action, transforming oxygen into ozone and producing changes in the color of glass and of barium platino-cyanid.