Chapter I: Gutta-Percha Patents (2)

To make a compound preferable to any yet in use for casting and moulding purposes, for water-proofing cloth, leather, and other articles and fabrics, and for coating ships’ bottoms, lining tanks and cisterns, &c., I mix with gutta-percha which has been first boiled in a bath of muriate of lime, and then masticated thoroughly, and while it is yet undergoing the process of mastication, a compound of shellac and borax, adding the same little by little as the mastication proceeds, and using more or less, according as it is desired to make the compound more or less tenacious. The compound of shellac and borax is prepared by boiling in a steam kettle over a common fire, five parts stick lac, or shell lac, or seed lac, with one part of borax, in so much water as will just cover these materials, and evaporating the water according to the thickness desired to be given to the compound. Any desired color may be given to this mixture of gutta-percha, shellac and borax, by mixing the requisite pigment or coloring matter with the shellac and borax compounds.

The improvements which I claim in my invention are as follows:

_First._ I claim the mode of making shoes and galoshoes of gutta-percha, combined with other materials first before described, in so far as regards the combination of elastic or flexible foundations with gutta-percha soles and uppers.

_Second._ I claim the employment of glass moulds to give a polish to the exterior or parts of the exterior of shoes and galoshoes made in whole or in part of gutta-percha, as before described.

_Third._ I claim the making of backs and stocks for brushes in whole or in part of gutta-percha, in order to give springiness to the same.

_Fourth._ I claim the making of backs and stocks for brushes in whole or in part of gutta-percha, as before described and exemplified.

_Fifth._ I claim the employment for painting, printing, or otherwise applying colors to articles and fabrics made in whole or in part of gutta-percha, and also to other articles and fabrics of the particular compound or vehicle hereinbefore specified, but without limiting myself to the exact proportions in which each of the materials has been directed to be used in such compound or vehicle, inasmuch as the said proportions may be varied without affecting the general result.

_Sixth._ I claim the employment, for all manufacturing purposes to which the same are applicable, of the several other improved preparations and compounds of gutta-percha specified under the fourth head of this specification, each in the peculiar combination of materials of which the same consists, and the peculiar process or processes by which it is prepared.

JAMES CARTLEY, of Harpenden, Hertford, manufacturing chemist, _for improvement in the manufacture of varnishes from resinous substances_. Patent dated January 11, 1849.

This invention consists,

_First._ In manufacturing in manner following, from resin spirit, and the gum resin called gutta-percha or gutta taban, a new compound or varnish which possesses the properties of being strongly adhesive and perfectly _water repellent_. The patentee puts into a pot three parts, by weight, of the gutta-percha or gutta taban, as imported or as it may be bought in the home market, and adds nine parts of crude resin spirit, (obtained by the destructive distillation of common resin) and subject them to a heat of from 120° to 140° Fah., stirring the mixture occasionally. The resulting solution forms a varnish which answers well for the coating of all coarse fabrics, such as tarpaulings, rick cloth, &c. But to obtain a varnish of a purer and better quality, suitable for fine articles, he rectified resin spirit, which he obtains by passing a current of steam through the crude resin spirit until the condensed product which comes over exhibits a specific gravity of about 0.870, at which point the process of distillation must be stopped, all products of a higher specific gravity being injurious to the quality of the spirit.

_Claim 1st._ The manufacture of the new varnish compounded of gutta-percha and resin spirit, (crude, rectified, or purified,) as before described.

_Second._ The manufacture of the new varnishes compounded of gum damar and resin spirit, or of gum mastic and resin spirit, whether such spirit is rectified and decolorized or rectified only, as before described.

WILLIAM HENRY BURKE, Tottenham, manufacturer. For improvements in the manufacture of air-proof and water-proof fabrics, and in the preparation of caoutchouc and gutta-percha, either alone, or in combination with other materials, the same to be applicable to articles of wearing apparel, bands, straps, and other similar useful purposes. Patent dated April 26, 1849.

_First._ Mr. Burke proposes to employ a compound of antimony instead of sulphur, for the purpose of rendering caoutchouc, gutta-percha, or their compounds permanently elastic, and unaffected by changes of temperature. The compound is prepared by mixing 1 part of crude antimony with 25 parts of crystallized carbonate of soda, or 20 parts of carbonate of potash, and 250 or 300 parts of water. The mixture is boiled from half an hour to three-quarters, and allowed to precipitate, when the supernatant liquid is run off. The precipitate is then dried and incorporated with the caoutchouc in a masticating machine in the proportion of from five to fifteen per cent. When bands or other articles are to be cut from blocks of caoutchouc, it is taken, while warm, from the masticating machine, and subjected to pressure for one or two days.

_Second._ It is also proposed to manufacture driving bands, by spreading the material dissolved in a suitable menstrum, with calender rollers, upon pieces of calico or other fabric, powdered with French chalk, to allow of the easy separation of the two, and to increase the rigidity and durability of gutta-percha driving bands, stripes of some fabric are to be affixed to the wearing parts, and both surfaces coated with the antimonized caoutchouc.

_Third._ To remove the shiny appearance of single texture garments, &c., Mr. Burke coats them with the antimonized caoutchouc, dissolved in some suitable menstrum, and mixed with ground silk or cotton, which is stated to have the effect of giving the article the appearance of cloth.

_Fourth._ Gutta percha soles and heels are proposed to be defended at the edges, where they are exposed to great wear and tear, with metal tips, shields, and guards.

CLAIMS.

_First._ The treating caoutchouc, gutta-percha, or their compounds, with the antimony compound.

_Second._ The mode of manufacturing driving bands.

_Third._ Coating water proof articles with antimonized caoutchouc, mixed with ground silk, cotton, or wool.

_Fourth._ The manufacture of gutta-percha soles and heels with metal tips, shields, and guards.

DESCRIPTION OF HANCOCK AND CO.’S PATENT GUTTA-PERCHA HEEL TIPS.

_From the London Mechanics’ Magazine, Vol. LI._

SIR:—We are reminded weekly by the advertisement in your Number, that gutta-percha “must be regarded as one of the blessings of a gracious Providence.” Doubtless this, as well as every other natural production, should be so regarded, although in the state in which it is left by Providence it would be of little use were it not for the additional blessings of ingenious-minded men, (as the Hancocks and others) by whose skill the crude gifts of Providence are manipulated and presented to our acceptance in a thousand beautiful and highly useful forms.

As weather-proof, and consequently _health-preserving soles_ for boots and shoes, gutta-percha most assuredly stands unrivalled. The application of this material to _heels_ has not hitherto been equally successful, from its being unequal to withstand the vast amount of wear and tear, to which this part of our understanding is subjected, one consequence of which is liability to spread, and become worn and ragged on its edges. For this defect, however, an efficient remedy has been provided in the compound heel tips, invented by Mr. B. Tyler, of Sheffield, and manufactured under Messrs. Hancock & Co.’s patent. The frame or border of this improved steel tip consists of a rim of cast iron or steel, furnished with tangs or projections. This frame is filled up with a tough compound of gutta-percha and cork, which encloses the tangs. The heel thus formed, requires no nailing to affix it to the boot or shoe, a coating of solution being sufficient for that purpose. Thus arranged, the metal and gutta-percha mutually aid and support each other; no spreading can take place, nor can the edges become worn or ragged. These tips never become loose, neither are they liable to become slippery. Having worn them for more than two years, I can with confidence assert them to be the best contrivance extant for the purpose. * * *

I am, Sir, yours &c.
WILLIAM BADDELEY,
_29 Alfred Street, Islington_.

EDWARD JOHN PAINE, Chancery Lane, London. For improvements in marine vessels, in apparatus for the preservation of human life, and moulding, joining and finishing hollow and solid figures, composed wholly or in part of a certain gum, or a combination of a certain gum; also for improvements in dissolving the aforesaid gums, and in apparatus or machinery to be used for the purposes above mentioned. Patent dated June 7, 1849.

* * * * *

A WATER PROOF VARNISH.—Mix together 1 lb. gutta-percha, 3 oz. gum opal, ½ lb. linseed oil, 8 oz. sugar of lead, 2 lbs. spirits of turpentine. Place the mixture in a tincture press, the cylinder of which is heated by a sand bath, and the produce is the varnish required.

A VARNISH WITH WHICH COLORS MAY BE MIXED, AND VERY SUITABLE FOR COATING ARTICLES IN GUTTA-PERCHA.—Take 100 lbs. gutta-percha, 18 lbs. 12 oz. gum opal, 50 lbs. linseed oil, 200 lbs. spirits of turpentine, and mix the whole together.

A VARNISH FOR UNPAINTED ARTICLES IN ROUGH WOOD.—Take 50 lbs. India-rubber, 100 lbs. gutta-percha, 30 lbs. gum opal, 70 lbs. gum damar, 150 lbs. linseed oil, 75 lbs. sugar of lead, 500 lbs. spirits of turpentine.

A VARNISH FOR ARTICLES OF METAL.—Take 100 lbs. gutta-percha, 20 lbs. gum opal, 75 lbs. linseed oil, 25 lbs. sugar of lead, 200 lbs. spirits of turpentine.

W. JOHNSON. Improvements in the treatment, preparation, or manufacture of sheet caoutchouc, and in the combination thereof with cloth and other fabrics. (A communication.) Dated October 3, 1856.

This relates to a mode of preparing sheets of caoutchouc, and combining them firmly with cloth and other fabrics, to produce goods for the manufacture of articles of various degrees of elasticity, and consists in preparing sheets of vulcanized caoutchouc, by desulphurizing their surfaces by first boiling the sheets in caustic alkali, and afterwards in salt pickle, to neutralize the alkali remaining on the sheet, and then washing the same. These sheets are then roughed on their surfaces, and the fabric to which they are to be applied is prepared by coating the surfaces thinly with a solution of caoutchouc dissolved in some solvent, and then thoroughly evaporating the solvent.

F. C. JEUNE. An improved manufacture of floor cloth. Dated May 26, 1856.

The patentee mixes in a masticating machine, India-rubber, (partly the waste of vulcanized rubber) and gutta percha, to produce a binding substance, and throws in ground cedar wood, or other vegetable dust, for increasing the bulk, and reducing the cost. When the mixing is effected, he adds fibrous substances in length, to impart toughness, and rolls the compound between rollers into sheets, which he submits to steam or hot air, to complete the adhesion of the particles.

C. GOODYEAR. An improvement in combining gutta-percha and asphalt or pitch. Dated August 30, 1856.

This consists in combining gutta-percha with asphalt or pitch, by the aid of hot water. They are, when desired, further combined with sulphur, with India-rubber, or other matters; and compounds are, when required, subjected to high temperature.

A. LORIMIER. An improvement in re-working vulcanized India-rubber. Dated October 20, 1856.

This consists in preparing the waste of vulcanized India-rubber by crushing the same between pressing rollers, then subjecting it to a considerable degree of heat, and whilst so heated causing it to be stirred, by which means the mass is progressively brought into a fluid state. It is then allowed to cool, but before becoming cold, a solvent of India-rubber is added, by which an India-rubber cement is produced.

GEORGE SIMPSON, Newington, Butts, chemist, and THOMAS FOSTER, Stratham, manufacturer. For improvement in manufacturing, or treating solvents of India-rubber, and of other gums or substances. Patent dated April 26, 1849.

_First._ Bisulphuret of carbon is placed in an iron still, the top of which opens into an earthen ware vessel containing pentuchloride of antimony, and a pipe leads from the top of this vessel, to the worm of an earthen-ware condensor. The still and first vessel are heated by steam jackets. The resulting product flows from the condensor to a reservoir, after which, it is rectified by lime and is then ready for use as a solvent. Before rectification, the India-rubber, gutta-percha, or other gum may be immersed in it, or exposed to its fumes and thereby rendered less liable to injury from the effects of cold or heat.

_Second._ Coal is purified and rendered applicable as a solvent of these gums by being subjected to a similar process, chloride of lime in solution being substituted for the pentuchloride of antimony.

_Claims._ 1st, The manufacture of chloride and bichloride of carbon, and its application as a solvent of India-rubber, gutta-percha, and other gums not soluble in water, and the mode of treating rubber, as described.

_Second._ The mode of treating coal oil with chloride of lime, for the purpose of obtaining a solvent of the before mentioned gums.

TO GUSTAVE EUGENE MICHEL GERARD, of Paris, in the Republic of France. For improvements in dissolving caoutchouc (India-rubber), and gutta-percha. [Sealed May 7, 1850.]

This invention consists in certain improved means of dissolving India-rubber and gutta-percha.

The patentee commences his specification by remarking that heretofore all solutions of India-rubber, whether clear or thick, have possessed great coherence and elasticity; the solvent, whatever it may have been, has always expanded the gum to a great extent; and as it is not until after this has taken place that the real act of dissolving the gum commences, a large quantity of the solvent is consequently required. * * *

The new process consists in mixing with the solvent (of whatever nature it may be) a certain quantity of alcohol, and macerating therein the India-rubber or gutta-percha, which will expand very little, and at the end of twenty-four hours, it will be in the state of paste, suitable for being moulded into any desired form. The patentee prefers to employ as a solvent, sulphuret of carbon, chloroform, sulphuric ether, naptha, essential oils of coal, or turpentine, and to add thereto from five to fifty per cent. of alcohol. The caoutchouc is mixed with the alcoholized solvents in all proportions, varying from equal parts to thirty parts of the latter, to one of the former, according to the thickness of the solution required, and after one or two days, the paste is submitted to the ordinary process of masticating, if the solution is made of equal parts, or when it is made of small quantities of the solvent; in other cases it is not necessary. The patentee adopts the same system when treating gutta-percha. He dissolves it in the alcoholized sulphuret of carbon, and dilutes it until it arrives at the consistence of thick syrup of sugar. In this state he permits it to remain three or four days, during which time, the impurities will be precipitated or rise to the surface; and then he draws off the gutta-percha in a state of complete purity.

It will be seen that the character of the invention is the mixture of alcohol with the solvent used for dissolving caoutchouc, and gutta-percha. As alcohol is the liquid which most quickly precipitates India-rubber from its solutions, the patentee avails himself of this property, by causing the alcohol, by means of a solvent, to enter into the interior parts of the India-rubber, or to detach all the adherent atoms which form the mass of the caoutchouc. By the addition of the alcohol, the particles are rendered less adherent among themselves, and are easily separated by pressure, retaining the form resulting from this pressure, and not returning to their ordinary form. On the solvent and the alcohol being evaporated, the caoutchouc will return to its original state. All liquids which possess the properties of alcohol may be mixed with the solvents. The principle of this invention is the causing matters which are not of a solvent nature, to be introduced into the body of the India-rubber by means of a solvent, such matters having the property to disunite the parts constituting the mass of India-rubber, and destroy the adherence of the particles, whether these matters are combined with the solvents, or introduced by themselves.

TO WILLIAM EDWARD NEWTON, of the Office of Patents, 66 Chancery Lane, London, England. For improvements applicable to Boots, Shoes and other coverings for, or appliances to the feet. [Sealed 6th of June, 1850.]

The first part of this invention consists in providing the under surface of India-rubber shoes, buskins, gaiters, boots, and over-shoes, with projecting metallic points, permanently secured in or to the soles, so as to render the same less liable to slip or slide, when used in walking over snow, ice, or other smooth or slippery surfaces.

In carrying out this improvement, the inventor procures short metallic points, in the form of headed rivets, in length very slightly exceeding the thickness of the sole, having a head of any convenient size. The diameter of the head is not material, but it should not be less than an ordinary rivet-head; and the size of the projecting portion should be, for light shoes, about 1/20 of an inch in diameter, which may be increased according to the size of the shoe,—care being taken not to render the shoe burdensome. Before the sole is applied to the shoe, these rivets or points are inserted through perforations in the sole, so that the heads shall rest upon the inner surface, and the points project through and beyond the outer surface, but so slightly that they can scarcely be felt in passing the hand over the surface. The sole thus prepared, is then applied in the usual manner, to the shoe. Another mode of providing the sole with such points, differs from the foregoing, in this respect only;—instead of using a number of headed rivets, the patentee takes a metallic plate, with projecting points, which may be cast for the purpose, so that when the points are inserted in the sole, the projecting points on the outer surface will be similar to those prepared with rivets as above described; while, on the inner surface, instead of presenting several heads, there will be one plate, which may be treated as one connecting head for all the rivets.

The third part of the invention relates to a method of making that kind of shoes known as clogs, and consists in making them of India-rubber, or the compounds thereof, and of what the inventor denominates India-rubber sponge, moulded of the desired form, with the upper part of the sole, which comes in contact with the sole of the shoe or boot, formed with a ring all around, and protuberances, so as to give the desired elevation with little weight.

The operator mixes sugar or resin with the India-rubber, prepared in the usual manner for vulcanizing, in the proportion of one-quarter of a pound of sugar or resin to each pound of India-rubber; and after the compound has been worked and treated in the usual manner, he forms the clog thereof, in a mould, and subjects it to the curing or vulcanizing process, by which it is rendered spongy and light. The mould is so formed as to make the sole thin, with a rim all round and protuberances within, for the boot or shoe to rest on, to give the foot the required elevation from the ground. The sole thus prepared, can be provided with a toe-piece and heel-strap, as described under the second part of the invention, or it may be provided with any other means of securing it to the foot.

The last part of the invention relates to a mode or modes of making India-rubber shoes or coverings for the feet pervious to perspiration, and yet impervious, under ordinary circumstances, to water or damp. This object may be effected by taking a quantity of India-rubber sponge and rolling it into thin sheets, which sheets may be made into boots, shoes, or coverings for the feet, and as they will be found to be covered with a great number of very fine holes, they will allow the perspiration to pass through, but will effectually keep out the wet.

It is preferred, however, to perforate the India-rubber by mechanical means, as a greater amount of regularity may be thereby attained, and the perforating process will be more under command. When the sheet rubber is made up into boots or coverings for the feet, it will be necessary either to leave those parts of the boot nearest to the sole, and most exposed to the wet, unperforated and impervious, or to cover those parts with an impervious material, leaving only the upper part pervious to perspiration. Under this head of the invention the claim is for making boots, shoes, and other coverings for the feet, pervious to the perspiration of the wearer, by making such articles of sheet rubber, previously perforated with minute holes.

TO ALFRED VINCENT NEWTON, of the Office of Patents, in Chancery Lane, London, England. For improvements in the preparation of materials for the production of a composition or compositions applicable to the manufacture of buttons, knife and razor handles, inkstands, door-knobs, and other articles, where hardness, strength and durability are required. (Sealed 4th of March, 1851.)[4]

Footnote 4:

This is one of the most important patents ever taken out, _being of
great practical utility_.

This invention relates to the preparation and treatment of caoutchouc and gutta-percha, either alone or in combination, for the purpose of producing a new manufacture or composition, applicable to various uses where hardness, strength and durability are required. The composition designed to be produced, will possess some of the characteristics of horn, ivory, jet, and may, according to the color imparted to it, be employed in place thereof; or it may be used as a substitute for costly woods, and be applied to furniture in the form of veneer.

In treating caoutchouc (India-rubber) for this purpose, it is combined with sulphur,—the best proportion being about equal parts, by weight, of each ingredient. By combining sulphur in this proportion, with the caoutchouc, and subjecting the compound to the curing operation, (hereafter to be described) a hard substance will be produced, but a still better result will be obtained by the introduction of magnesia or lime, or of carbonate, or sulphate of magnesia, or carbonate or sulphate of lime, or calcined French chalk, or other magnesian earth, into the composition, in which case, the following proportions will be found highly advantageous, viz.; one pound of caoutchouc, half a pound of sulphur, and half a pound of magnesia, or lime, or carbonate or sulphate of magnesia, or carbonate or sulphate of lime, or calcined French chalk, or other magnesian earth. The proportions specified in both of these compounds, may be considerably varied without materially changing the result; but in no case is it desirable to use a much less quantity of sulphur than four ounces to every pound of caoutchouc. With either of these compounds just described, gum lac, or gum shellac, may be combined to great advantage,—say, in the proportion of from four to eight ounces of gum lac to every pound of caoutchouc. Rosin, oxides or salts of lead or zinc, of all colors, and other similar substances, both mineral and vegetable, may be added in small quantities, to either of the compounds, for the purpose of imparting a polish, or a color thereto, and for making the mixture work more easily; but no precise rule for these additions can be given; nor, indeed, is it necessary, as the taste and judgment of the operator will be his guide in this particular.

The compounds produced according to the above plans, are next treated in the manner to be presently described; but, as this process is equally applicable to the treatment of other compositions included in this invention, the patentee first explains of what these compositions consist. When using gutta-percha in lieu of India-rubber, the inventor takes certain proportions of gutta-percha, sulphur and magnesia, or lime, or a carbonate, or a sulphate of magnesia or lime, or calcined French chalk, or other magnesian earth, and mixes them in a convenient manner.

The portions preferred are the following, viz.—one pound of gutta-percha, six ounces of sulphur, and from six to eight ounces of either magnesia or lime, or a carbonate, or a sulphate of magnesia or of lime, or calcined French chalk, or other magnesian earth. Instead of using the specified proportion of the magnesia or lime, or of the carbonate or sulphate of magnesia or lime, or of calcine French chalk or other magnesian earth, the same proportion of any two or more of these substances combined, may be employed, care being taken that the quantity of this third ingredient in the composition does not vary from the proportion of six or eight ounces. These proportions may, however, be slightly varied, without materially changing the result.

To the composition above specified, a fourth ingredient may be added, viz., gum shellac, by which a still better article will be produced—the body thus obtained being stronger and more easily worked. The quantity of shellac, in such case, should be about four ounces to every pound of gutta-percha.

Resin, oxide or salts of lead or zinc, of all colors, and other like substances, both mineral and vegetable may be added, in small quantities, to either of the above compositions, for the purposes before stated with respect to the India-rubber composition.

The compounds described may be mixed by a masticating machine or other means, until the several ingredients are thoroughly incorporated. The mineral ingredients should be finely divided, and good results are obtained by reducing them before mixture, to an impalpable powder.

When rolled or moulded, the compounds are then to be “cured.” This is effected by exposing the compound to a high degree of artificial heat, using for this purpose either steam, hot water, or hot air. The degree of heat to which this compound is to be exposed, and the duration of its exposure, will depend somewhat upon the size and thickness of the article; but in ordinary cases the heat should be raised to about 260° or 270°, Fah., and the compound exposed to such heat for about four hours; as a general rule, however, it may be stated that the heat should range from 250° to 300°, Fah., and the time of exposure from two to six hours. The compounds or compositions by undergoing this heating or curing operation, will become of a hard, stiff character, in many respects resembling tortoise-shell, horn, bone, ivory, and jet. In the compounds described as compositions of caoutchouc, considerable proportions of gutta-percha may be substituted for caoutchouc (rubber) without injury; and, in the compounds described as compositions of gutta-percha, considerable proportions of caoutchouc may also be substituted for gutta-percha without injury * * * *

The compositions, when hardened, may be worked like wood or bone; but, in some instances, it is proposed to mould, shape, or otherwise treat the compositions so as to render them better suited to the purpose for which they are intended, prior to submitting them to the hardening process. Thus when it is desired to use these new compositions in combination with common flexible vulcanized caoutchouc, the parts intended to be hardened may be united to a connecting band, or connecting pieces of flexible vulcanized caoutchouc, by cementing or pressing together the surfaces required to be joined, before the heating or curing process has been effected; by which means, during the process of curing, the abutting elastic and non-elastic surfaces will become firmly united together.

* * * * *

Another mode of applying the composition consists in uniting them in their plastic or green state with iron, or other metals or rigid substances, which will bear a high degree of artificial heat without alteration or damage, roughened in such portions of its surface as are intended to be brought into contact with the compound of caoutchouc or gutta-percha, and the compound is then applied to the roughened surface of the article. When it is desired that the compound of caoutchouc or gutta-percha shall serve as a covering to the iron or other substance, a thin sheet of the compound (sometimes one thirty-second part of an inch in thickness or less) is pressed with great care, upon the iron or other substance, so as to expel all air from between the adjoining surfaces, and to cause the most perfect union and adhesion, as the coated article is bound with strips or ribbons of cloth, or other suitable material, whereby the compound is kept in close contact with the article during the process of hardening. The combined materials thus treated, will be found to possess the qualities desired—the iron or other substance giving strength and the compound giving a hard and durable surface. In this way may be produced many articles used in and about harnesses or carriages, such as saddle trees, buckles, terrels, bits, stirrups, martingale rings, dasher-irons, and articles intended to be used as furniture, either in whole or in part, and a great variety of other useful objects.

A. FORD. _Preparing and dissolving in naptha or oil of turpentine, vulcanized India-rubber for the purpose of water-proofing, and for all or any of the other purposes for which the same not so prepared and dissolved is now applicable, and expressly for the coating of iron ships’ bottoms._ Dated June 27th, 1856.

The inventor first cuts the vulcanized India-rubber into small pieces, and places it in a boiler, having within it an agitator or stirrer, kept in constant motion during the process. The only openings into this boiler are a main hole with a screw top; a safety-valve which comes into action only when the pressure on the inner surface of the boiler exceeds 25 lbs. to the square inch, and the opening occasioned by the passage of the stem of the agitator, which passes in at the summit. He then applies heat in such a manner as that three-fourths of the outer surface of the boiler shall be at once exposed to its influence, and at a temperature of never more than 300° Fah.; and he continues the same until the India-rubber shall be reduced to the consistence of dough, when he takes it out, and having mixed with it a sufficient portion of French chalk in powder to remove its adhesiveness, passes it a few times through metal rollers, after which it is capable of being dissolved in naptha or oil of turpentine in the manner of ordinary India-rubber. The _rationale_ of the process is, that by means of the heat applied to the boiler, he decomposes a small portion of the vulcanized India-rubber, whereby a gas is generated which, filling the interior of the boiler, acts upon the remaining portion, and softens it. The not allowing the gas to escape is, therefore, a very important feature.

N. S. DODGE. _Improvements in treating vulcanized India-rubber or gutta-percha._ Dated January 18th, 1856.

This invention relates to a mode of treating vulcanized India-rubber, for rendering scraps or waste pieces, such as old shoes, &c., fit to be re-used without requiring to be vulcanized. The material is reduced into small pieces, and placed in a vessel hermetically closed, and to it is added pure alcohol and bisulphate of carbon (¼lb. of the former, and 10 lbs. of the latter, to 100 lbs. of the material,) the alcohol and the bisulphate being previously mixed together, and then poured over the material to be treated. The vessel is then closed air-tight for two hours, at the end of which the process is complete.

W. A. TURNER. _Improvements in the manufacture of elastic tubing._ Dated February 29th, 1856.

The invention relates to tubing made of India-rubber and gutta-percha, either separately or in combination, and is designed for rendering such tubing capable of withstanding a pressure of from 50 to 100 lbs. on every square inch of surface. The novelty consists in combining with the aforesaid material a rigid substance, such as a helix or a series of rings of metal or other material.