Chapter VI

*Eye.*--Harden the eye of a recently killed bullock, cat, or other animal in formal (p. 23), puncturing the sclerotic in places to allow the hardening fluid to penetrate. In about a week make a horizontal section through the eye. The anterior half (the lens having been removed) may be satisfactorily cut in gum. Sections of the crystalline lens are not very satisfactory. The best way to get specimens of the fibres is to tease a piece of the fresh lens of a fish (_e.g._, a cod) in a 1/40 per cent. aqueous solution of eosine. Wash the eosine off the slide with 1/2 per cent. acetic acid, and mount in Farrant’s solution.

The posterior half of the eye should be embedded in celloidin, as otherwise it is extremely difficult to get sections of the retina in its proper relation to the other coats.

Mount some specimens unstained. Stain others with the ordinary stains.

*Internal ear.*--Decalcifying the temporal bone of a cat, dog, guinea pig, &c., in chromic and nitric fluid. As soon as the bone is decalcified complete the hardening of the soft parts in methylated spirit, embed in celloidin, and cut sections in the longitudinal axis of the cochlea. Owing to the extreme hardness of the bone in adults it will be found best to use the petrous bone of newly born animals.

The semi-circular canals will be most readily studied in the temporal bone of fishes, or of birds, _e.g._, the common fowl. They also must be cut in celloidin, and stained in the ordinary way.

*Nose and olfactory epithelium.*--It is difficult to obtain specimens from the human subject, but very satisfactory preparations may be made from the dog, or more conveniently in a new born puppy where the bones are still cartilaginous. Harden the latter in Müller’s fluid, decalcify adult specimens in chromic and nitric fluid. Specimens of ciliated epithelium, &c., will be obtained from the lower part, and of the special olfactory epithelium from the upper part. Stain in eosine and hæmatoxyline.

*Lungs.*--Carefully remove the lungs of a cat without injuring the bronchi or trachea. Introduce a cannula into the trachea and gently inflate the trachea with air. Ligature the trachea and place the lung in Müller’s fluid, a weight being attached to keep the organ submerged. Harden for about six weeks, and then make sections of the various parts.

To demonstrate the endothelium of the alveoli, inject instead of air, nitrate of silver. Allow it to remain in for half an hour, then remove it by washing, and harden in Müller’s fluid.

Beautiful casts of the alveoli, &c., may be obtained by placing a cat’s or human lung under the receiver of an air-pump, and when the air is completely exhausted, injecting fusible metal into the bronchus. The lung tissue is then removed by corrosion or by maceration. Portions of the casts should be removed, fixed in a glass cell with a spot of Canada balsam, and examined by reflected light.

*Thyroid gland.*--Best obtained from a young subject either human or an animal.

Harden in Müller’s fluid. Stain in picrocarmine or eosine and hæmatoxyline. Also stain sections in safranine, which stains the colloid material, and also picks out any colloid formation in the cells themselves.

*Thymus.*--Remove from a fœtus or a very young animal, and prepare in the usual way.

*Tongue.*--That of the cat or rabbit serves very well.

Ordinary transverse sections should be made, and also sections through the circumvallate papillæ in order to study the “taste buds.”

*Salivary glands.*--Those of a cat or dog do very well.

Sections should be made from each of the three glands.

*Stomach.*--That of the cat or dog should be studied. The organ must be removed immediately after death before any post-mortem digestion of the coats has occurred. The stomach should be opened, washed gently and pinned out flat, with as little stretching as possible on a piece of wood, and hardened in Müller’s fluid.

Sections should be made (_a_) longitudinally through the cardiac end to show the transition from the œsophageal to the gastric mucous membrane, (_b_) from a portion of the greater curvature, (_c_) longitudinally through the pyloric valve.

Eosine and hæmatoxyline form the best stain for the alimentary canal.

*Intestine.*--Prepare in the same way as the stomach. Make sections from (_a_) the upper part of the duodenum to show Brunner’s glands, (_b_) the ileum, (_c_) a Peyer’s patch, (_d_) the vermiform appendix, (_e_) the colon.

*Liver.*--Make an injection of one specimen with carmine and gelatin (p. 120). Harden in methylated spirit. Others should be hardened in Müller’s fluid and stained in the usual way.

*Kidney, supra-renal, and pancreas.*--Same preparation as for liver.

*Spleen.*--Harden in Müller’s fluid.

Mount one section unstained. Shake another up with water in a test tube to shew the structure of the pulp. Stain others in eosine and hæmatoxyline.

*Bladder.*--Must be removed and pinned out immediately after death, as otherwise the epithelium will be macerated off. Consequently it must be taken from an animal, as a cat. Harden in osmic acid. Cut in celloidin as the coats are very apt to become detached.

*Penis* and *testis*.--Readily obtained from dog, cat, or rat.

Stain with eosine and hæmatoxyline.

*Uterus, ovaries, and Fallopian tubes.*--May be obtained from the post-mortem room or from the lower animals. Harden in Müller’s fluid, and make sections from the cervix, the body of the uterus, the Fallopian tube, and the ovary.

Stain with eosine and hæmatoxyline.

*Embryological specimens.*--For systematic work special manuals should be consulted.

Specimens should be hardened in osmic acid or in Müller’s fluid, and cut in celloidin, or paraffin.

*Cloudy swelling.*--Specimens are obtained from organs of subjects who have died in the early stage of some fever. They should be always hardened in Müller’s fluid, as the appearances alter if the tissue is kept in spirit for any length of time.

*Fatty degeneration.*--Prepare from patients who have died of exhausting diseases, phosphorus poisoning, &c.

Stain in osmic acid. Mount in Farrant’s medium and keep in the dark.

*Mucoid degeneration.*--Study in goblet cells of normal intestine or of ovarian cysts. There are no satisfactory selective stains for mucin.

*Colloid degeneration.*--Occurs in the thyroid gland, in the tubules of the kidney in many diseases, and the prostate of the old.

Stain in safranine.

*Waxy or lardaceous degeneration.*--Best studied in liver, spleen, or kidneys. It should be searched for in persons who have died from a long illness, accompanied by suppuration, _e.g._, phthisis or bone disease. Mount one section unstained, stain another in methyl violet, a third in a weak solution of iodine, and examine the latter at once both by transmitted and reflected light. The iodine stain is not permanent. Another section should be stained in osmic acid, followed by methyl violet, as waxy and fatty degeneration frequently co-exist.

*Hyaline degeneration.*--Seen in the arterioles of the spleen in some cases of typhoid and diphtheria. The ordinary staining methods must be used.

*Calcareous degeneration.*--Occurs after fatty degeneration in gummata and in atheromatous arteries. It also occurs in the matrix of the costal cartilages after middle life. Mount one section unstained and examine if possible with the polariscope. Stain others in safranine.

*Pigmentary degeneration.*--May be studied in brown atrophy of heart, nutmeg liver, &c. It is also seen well in spinal and cerebral nerve cells of the aged. Harden in Müller’s fluid and mount sections unstained.

It will be unnecessary to recapitulate the methods for hardening the various diseased organs as the directions for the normal organs hold good. If the presence of micro-organisms be suspected, harden in methylated spirit or absolute alcohol, but as a rule both for diseased organs and tumours Müller’s fluid will be found the most satisfactory reagent for general use.

It sometimes happens, however, that it is inconvenient to wait several weeks, until the Müller’s fluid has hardened the specimen sufficiently, before making sections. In this case the best plan is to make fresh sections, or else to cut a slice about one-eighth of an inch thick, and harden for about three days in plenty of methylated spirit, or in formal (p. 23).

*Tumours.*--Müller’s fluid should be employed, unless a more rapid agent is required.

Methylated spirit may be used in the case of epithelioma, adenoma, &c., but for sarcoma, myxoma, tumours containing cysts or much blood, Müller’s fluid yields by far the best results.

BOOKS OF REFERENCE.

Methods in Microscopical Anatomy--_Whitman_.

Practical Pathology--_Woodhead_.

Textbook of Bacteriology--_Crookshank_.

Manual for Physiological Laboratory--_Harris_ and _Power_.

Practical Histology--_Fearnley_.

Practical Pathology and Histology--_Gibbes_.

Journal of Microscopical Society.

Methods and Formulæ--_Squire_.

The Human Brain--_Goodall_.

Practical Bacteriology--_Kanthack_ and _Drysdale_.

Methods of Microscopical Research--_Cole_.

INDEX.

Abbe’s condenser, 11

Absolute alcohol, 21

Acetate of copper, 89

Air bubbles, removal of, 56

Alum carmine, 76
hæmatoxyline, 68, 70

Amyloid degeneration, 149

Aniline blue-black, 94
oil, 102, 108
oil water, 107

Apparatus required, 1

Areolar tissue, 133

Bacteria, stains for, 103

Balsam bottle, 58

Barrett’s logwood solution, 69

Bevan Lewis’s method, 94

Bichromate of potassium, 17

Bismarck brown, 104

Bleaching solution, 27

Blood crystals, 130

Blood, methods of examining, 113

Blood-vessels, injection of, 120

Blue injection mass, 121

Bone marrow, 136

Bone, sections of, 136

Borax carmine, 75

Brain, methods of staining, 94

Buckley’s modification of Golgi’s method, 99

Calcareous degeneration, 149

Canada balsam solution, 61

Carbolic acid, 23

Carmine, 74
injection mass, 120

Cathcart microtome, 39

Cathcart-Frazer microtome, 42

Cedar oil, 8, 63

Celloidin, 30

Cementing cover-glasses, 65

Chloral hæmatoxyline, 92

Chloride of gold, 82, 94

Chromic and nitric decalcifying fluid, 26

Ciliated epithelium, 132

Circulation in frog’s foot, 141

Clarifying sections, 63

Clearing agents, 63

Cloudy swelling, 148

Clove oil, 63

Colloid degeneration, 149

Columnar epithelium, 132

Corrosive sublimate hardening, 23
staining, 100

Cover-glasses, cleansing of, 57

Cover-glass preparations, 111

Decalcifying solutions, 26

Dehydration, 63

Eau de Javelle, 27

Ebner’s solution, 27

Ehrlich-Biondi fluid, 85

Ehrlich’s hæmatoxyline, 70
method of fixing blood-films, 116
method for tubercle bacilli, 110

Ehrlich-Gram method for staining bacteria, 108

Elastic cartilage, 135
tissue, 133

Embedding methods, 29

Endothelium, 131

Eosine, 72

Eosine and hæmatoxyline, 73

Epithelial cement, 131

Ether spray microtome, 39

Fæces, staining for bacilli, 112

Farrant’s solution, 59

Fat, removal from sections, 59
staining of, 134

Fatty degeneration, 148

Fearnley’s injection apparatus, 123

Ferrier’s fuchsine solution, 117

Flemming’s solution, 25

Flotation of sections, 55

Folded sections, treatment of, 58

Formal, 23

Fresh sections, 52

Fuchsine, 104

Gentian violet, 104

Gibbes’ stain for tubercle bacilli, 111

Gold chloride, 82, 94

Golgi’s silver method, 96
sublimate method, 99

Gram’s iodide solution, 105
method for staining bacteria, 107

Green injection mass, 122

Gum, 29

Hæmatin crystals, 131

Hæmatoidin, 131

Hæmatoxyline, Ehrlich’s, 70
Kleinenberg’s, 70
Schuchardt’s, 68
Sihler’s, 92
Weigert’s, 88

Hæmoglobin crystals, 130

Hardening processes, 15

Hyaline cartilage, 135
degeneration, 149

Ice freezing microtome, 46

Immersion lenses, 8

Injection of blood-vessels, 120
pulmonary alveoli, 145

Internal ear, 143

Intestines, 146

Iodine solution, 105

Jung’s ether spray microtome, 45

Kleinenberg’s hæmatoxyline, 70

Lardaceous degeneration, 149

Lithio-picrocarmine, 79

Lithium carmine, 74

Liver, 147

Löffler’s methyl blue, 104

Logwood, 68

Lymphoid tissue, 134

Marchi’s fluid, 24

Marrow, 136

Methyl blue, 101, 104
violet, 83

Methylated spirit, 19

Micro-organisms, stains for, 103

Microscope, 6

Microtome, Becker, 49
Cambridge rocking, 49
Cathcart, 39
Cathcart-Frazer, 42
Jung, 45
Schanze, 47
Swift’s, 49
Williams’, 46

Mould for paraffin embedding, 36

Mounting methods, 55

Mucoid degeneration, 148

Muscle, 138

Muir’s method of hardening films, 116

Müller’s fluid, 17
and formal, 20
and spirit, 20

Neelsen’s stain for tubercle bacilli, 110

Nerve cells, stains for, 94
endings, 139
fibres, stains for, 87

Nissl’s aniline method, 101

Nitrate of silver, 82

Nitric acid as hardening agent, 25
decalcifying agent, 26
decolourising agent, 110

Normal salt solution, 53

Nose piece, 9

Objectives, 7

Oil of bergamot, 63
cedar, 8, 63
cloves, 63
origanum, 63

Osmic acid as hardening agent, 21
staining reagent, 81

Pal’s method, 86
solution, 90

Paraffin, 34

Picrocarmine, 78

Pigment cells, 134

Pigmentary degeneration, 150

Plane iron microtome knife, 42

Rapid hardening, 150

Retina, 143

Safranine, 85

Salivary glands, 146

Schäfer-Pal method, 91

Schanze microtome, 47

Schuchardt’s hæmatoxyline, 68

Sihler’s chloral hæmatoxyline, 92

Silver nitrate, stain for nerve cells, 96
epithelial cement, 131

Skin, 142

Spinal cord, 86, 142

Spleen, 147

Sputum, staining of, 111

Squamous epithelium, 131

Staining methods, 67 _seq._

Stomach, 146

Striped muscle, 138

Sulphuric acid, 105

Sweat glands, 142

Tendon, 133

Testing a microscope, 13

Thymus gland, 145

Thyroid gland, 145

Toison’s fluid, 118

Tooth, sections of, 137

Transitional epithelium, 132

Tubercle bacillus, stains for, 110

Tumours, hardening of, 150

Unstriped muscle, 139

Urine, examination for bacilli, 112

Uterus, 148

Von Ebner’s decalcifying solution, 27

Waxy degeneration, 149

Weigert’s hæmatoxyline method, 88
method for staining bacteria, 106

Williams’ ice freezing microtome, 46

Woodhead’s injection mass, 120

Xylol, 61

Ziehl’s carbol-fuchsine, 105

End of Project Gutenberg's Section Cutting and Staining, by Walter S. Colman