BM UN/VERSITY OF rA ^ DAT E DUE WlAY 16 UUWW 1 " • ' i 1 CAYLORO 1 PRINTED IN USA. cri- U Is 3fL. WL 300 L677h 1882 ""imMlM Ill'J'.f.iSl.f.'i'i^i?... 5A.N..qiEG0 E 3 1822 01030 2909 ::> Ub77 \ ^V\ THE HUMAN BEAIN HISTOLOGICAL AI^D COAESE METHODS OF RESEARCH THE HUMAN BRAIN HISTOLOGICAL AND COARSE METHODS OF RESEARCH A MANUAL FOR STUDENTS AND ASYLUM MEDICAL OFFICERS By W. BEYAN lewis, L.R.C.P. (Lond.) DEPUTV MEnlCAL SUl'ERIXTEXnENT TO THE WEST BIDINO LUNATIC ASYLUM LONDON AND A. CHURCHILL, NEW BURLINGTON STREET 1882 PREFACE. In these days of a voluminous scientific literatui'e the • appearance of every new manual demands some justifica- tion ; a genuine want can alone excuse additions to an already extensive series of handbooks of scientific methods of research. The onus 2J)-obandi of this want rests, of course, with the author,, and can in the present instance be readily met. Prompted by the editors of Brain, as well as by a personally-felt need for a concise summary of methods of examination of the nervous centres, the author contributed to the pages of that journal a series of articles on " Methods of Preparing, Demonstrating, and Examining Cerebral Structure in Health and Disease." An appeal thus made to what was regarded as a gene- rally prevailing want amongst asylum medical officers and students, was met with signs of cordial approval, and the frequently expressed wish for the re-appearance of these articles in a separate and convenient form. Such expressions of approval form the author's justi- fication for this Manual of Methods. West Riding Asylxtm, April, 1882. CONTENTS. PART I. Coarse Examination of the Brain and its Membranes. CHAPTER I. The Duka Mater and Venous Sinuses. C I'AOE General Anatomical Features— General Appearance at the Vault — Examination of the larger Venous Sinuses — GenenU Appear- ance at the Base . . . . . . - . • • . • • . • 3-S CHAPTER 11. The Aeachnoid and Pia Matek. General Anatomical Features — Coarse Examination of the Mem- branes.. .. .. .. .. .. .. .. ..iJ-H CHAPTER 111. The Aetekial System of the Beain. Dissection — Arrangement of the Blood-supply in Circle of Wiliis— Superficial Examination of the Arterial Tunics — Capacity of the Arteries at the Base — Vessels of the Pia Mater — Nutrient Vessels at the Base . . . . . . . . . . . . 15-25 CHAPTER IV. Physical Properties of the Grey and "White Substance of the Brain. \ CONSISTENCE 27 Conditions modifying Normal Consistence — Estimation of Textural Cohesion— Consistence of the Normal Brain — Reductions in Vlll CONTENTS. PAUli Consistence: 1. Putrefactive Changes; 2. Indications of Softening; 3. White Softening of the Brain ; 4. Limited Foci of Softening; 5. YeUow Softening of the Brain; 6. Eed or Inflammatory Softening of the Brain ; 7. Simple OEdematous Conditions of the Brain— Augmented Consistence: 1. Super- ficial Scleroses; 2. Hypertrophy of Neuroglia; 3. Cicatricial Formations; 4. Disseminated Sclerosis; 5. Descending Sclerosis . . . . , . . . . . . . . . . . 45 § COLOUR 45 Pallor: 1. Partial Mottling and Laminated Pallor; 2. General Diffused Pallor— Kedness : 1. Congested Zones ; 2. Patchy Kedness of Cortex ; 3. Puncta Vasculosa — Kesultsof Increased Intra-Cranial Pressure — Results of Increased Intra-Thoracic Pressure 55 § VOLUME . . . . 55 Volumetric Methods for the Brain : 1. Dr. Hack Tuke's; 2. Other Methods ; 3. By Stevenson's Apparatus— Estimation of Cranial Capacity : 1. Dr. Hack Tuke's ; 2. Professor Flowers' ; 3. Paraffin Method ; 4. Broca's Eesiilts .. ,. ..60 § WEIGHT 60 Gravimetric Methods— Absolute Weight of Brain — Specific Gravity by : 1. Bucknill's Method ; 2. Sankey's Method ; 3. Stevenson's Apparatus — Proportion of White and Grey Substance (Danilewsky) .. .. .. .. ..68 CHAPTER V. Removal akd Dissection of the Beain. § EXTERNAL ASPECT OF THE BRAIN 69 § EXAMINATION OF INTERNAL STRUCTURE OF THE BRAIN 71 CHAPTER VI. StrPEEFICIAL TOPOGKAPHY. § GENERAL REFERENCE TO THE PHOTOGRAPHS . . 77 § LIST OF SYNONYMS FROM ECKER , , 78 CONTENTS. IX PAKT II. Minute Examination of the Brain. PAGE CHAPTER VII. The Methods of Reseakch Conteasted 85 CHAPTER VIII. MlCEOTOMES FOE IMBEDDING AND FeeEZING. Microtomes for Imbedding : 1. Stirling's ; 2. Ranvier's ; 3. Ruther- ford's; 4. Roy's; 5. Schiefferdecker's ; 6. For Large Sections — Microtomes for Freezing: 1. The Ether Freezing Micro- tome (Bevan Lewis) ; 2. The Ice and Salt Freezing Microtome (Rutherford) ; 3. The Quekett Club Freezing Microtome ("Williams) 89-99 r CHAPTER IX. Peepaeation of Haedened Beaijt. § HARDENING BY CHROME 102 1. MiiUer's Fluid and Potassiimi Bichromate ; 2. Potassium Bichromate and Chromic Acid (Rutherford) ; 3. Iodized Spirit and Potassium Bichromate (Betz) ; 4. MiiUer's Fluid and Ammonium Bichromate (Hamilton) ; 5. Chromic Acid (Lockhart Clarke) .. .. ..105 § HARDENING BY OSMIC ACID (EXNER'S PROCESS) . 105 § SUMMARY OF PROCESSES FOR HARDENING . . . 106 § IMBEDDING AND SECTION-CUTTING 107 The Imbedding Mass— Section- Cutting — The Section-Blade— Sub- sequent Treatment of Sections — Sections through a Hemi- sphere — List of Apparatus Required ., .. .. ..114 § STAINING AND MOUNTING 115 Hsematoxylin Staining: 1. The Dye; 2. The Staining Process; 3. Notes on the Reaction of the Dye — Cai-mine Staining : 1. The Dye; 2. The Staining Process; 3. Notes on the Reaction of the Dye — Picro-cannine Staining : 1 . The Dye ; 2. The Staining Process ; 3. Notes on the Reaction of the Dye — Aniline Blue-black Staining : 1. The Dye ; 2. The Staining Process ; 3. Notes on the Reaction of the Dye — Osiuic Acid Staining (Exner' s Process) — On the Use of Compound Pigments : 1. Ajiiline Picro-carminate ; 2. Picro-aniline Staining ; 3. Osmium and Picro-carmine ; 4. Hsematoxylin with Aniline ; 5. Eosin and Logwood ; 6. Picro-carmine and Iodine Green .. 131 X CONTEXTS. PAGE § STAINING OF SPECIAL REGIONS OF THE BRAIN AND SPINAL CORD 131 Staining the Cortex Cerebri — Staining the Cortex Cerebelli — Staining the Central Medulla and Ganglia— Staining the Pons, Medulla Oblongata, and Cord — List of Apparatus Required ... . . . . . . . • • • • • . . 1 3o CHAPTER X. Pkepaeation of Nekvous Tissue in the Fuesh State. § PREPARATION OF SECTIONS FROM FROZEN TISSUES . . 137 The Freezing Method— Staining Fresh Sections of Cortex — Mounting for Permanent Preservation — Staining Fresh Sec- tions of Central Medulla 143 § PREPARATION OF NERVOUS TISSUES BY DISSOCIATION 144 Gerlach's Method for the Spinal Cord — Rapid Method for the Multipolar Cells of Cord — Rapid Method for the Ganglion Cells of the Cortex Cerebri : 1. First Stage, The Film; 2. Second Stage, Staining the FUm ; 3. Third Stage, Permanent Mount- ing — Examination of the Neuroglia: 1. Boll's Method; 2. Ranvier's Method; 3. Mierzejowski's Method — Dissection of MeduUated Strands in the Fresh Brain — Remarks ni^on Dissociation of Nerve-CeUs .. .. .. .. ..1-49 PAET III. List of Keagents and Mounting Media. List of Hardening Reagents — Stock Solutions and Special Solu- tions .. .. .. .. .. .. .. .. ..153 List of Staining Reagents — Stock Reagents and Special Solutions 155 List of Macerating and Dissociating Reagents ,, ., ..158 List of Media for the Mounting of Preparations . . . . . . 159 List of Cements . . . . . . . . . . . . . . . . 159 LIST OF ILLUSTRATIONS. Tm. PAGE 1. Diagram Illustrative of the Effects of Embolic Plugging (after Rindfleisch) . . . . . . . . . . . . . . . . 36 2. Specific Gravity Test Apparatus . . . . . . . . . . 63 3. Stevenson's Displacement Apparatus . . . . . . . . 65 4. Convolutions of the Cerebnim as seen at the Vertex (after Bischoff) 5. Convolutions of the Cerebrum, as seen at the Median Aspect (after Bischoff) 6. Convolutions of the Cerebrum, as seen at the Base (after Bischoff) 7. Convolutions of the Cerebrum, Lateral Aspect (after Bischoff) . . 8 The Avithor's " Ether Freezing Microtome " (Original Model) . . 93 <J. The Author's " Ether Freezing Microtome " (New Foi-m) . . 94 10. Rutherford's Freezing Microtome .. .. .. .. .. 96 1 1 . Williams' Freezing Microtome , . . . . . . . . . 98 THE HUMAN BEAIN. HISTOLOGICAL AND COARSE METHODS OF RESEARCH. INTEODUCTION. Important and necessary as are the minute investigations made by microscopic agency into the normal structure of the brain or its pathological deviations, we must guard ourselves from the very serious error of considering this method as essential or exclusively necessary in these studies. This error is a common one, and is too apparent to need mucli comment upon my part ; for all who are engaged in the prosecution of cerebral histology must have recognized the prevailing tendency to disregard the naked-eye appear- ances of the brain, or to consider them as of very secondary import compared with a minute investigation aided by the complex armamentarium of the microscopist. If any of my readers are possessed of this notion I would ask them at the outset to rid themselves immediately of so fallacious an idea as one which, if fostered, must prove a serious obstacle to the acquirement of that intimate acquaintance with the true significance of the varied appearances presented by normal and diseased tissues. The skilled obstetrician recognizes as an invaluable acquirement that tactus eruditus which a constant and intelligent employment of a special XIV INTRODUCTION, sense can alone confer ; and no less should the histologist endeavour to obtain a special visual tact, a highly refined and educated visual power, which can alone enable him to recog- nize by the unaided eye appearances which pass wholly unnoticed by the casual observer. I cannot too strongly insist upon this point, for he who would successfully study the morbid anatomy of the brain must, as in the morbid anatomy of other tissues, begin seriously to educate the eye to the coarse appearances presented to the unaided vision. The employment of a hand-lens of 2 to 4 inches focal length will prove of service here, the naked-eye appearance being contrasted with the magnified field, and the eye thus educated up to recognizing characters which without the aid of the lens were previously indefinite or unrecog- nizable. Nothing beyond repeated and energetic efforts in this direction will enlarge the area of the visual field and present to the mind the manifold appearances which consti- tute an unbroken whole, and wliich are absolutely necessary to a refined interpretation of the picture presented to the mind's eye. Repeatedly have I had occasion to observe that the student, after a full curriculum of hospital training — a training which should pre-eminently involve the high culture of the sense of sight, hearing, and touch — fails wholly to appreciate the most obvious abnormalities of the cerebro- spinal tissues, and this because he has neglected to tutor the eye so far as to learn what to look for, and how to look for it. If you place before him the brain of a case of chronic mania, without coarse lesion, and note his observations upon the appearances of a section across the hemisphere, it will be found that beyond a statement that the grey matter is pale, anoemie, and wasted, that the white matter is altered in con- sistence, and presents numerous coarse vessels, his untutored eye teaches him no more ; and should he be examined even for the grounds upon which these statements are made, a too evident vagueness mil be apparent — his ideas on relative depth of cortex or anoemic states of the brain and consistence of its tissue are ^ugcd by no mental standard, and are INTRODUCTION. XV remarkable only for their indefiniteness. The practised eye of the histologist, however, sees far more : the relative depth of cortex in various regions ; the relation borne by this depth to normal standards ; the varied depths of the several laminoe of the cortex, their distinctness of outline, general and local vascularity, as well as the deviations in hue dej^endent upon fatty or upon pigmentary changes. The oedematous, degene- rated aspect of the medullary tracts, the presence of minute sclerosed patches, and a host of other morbid appearances, present to his mind a picture which the unpractised eye wholly fails to appreciate. To those who are liable to err in the direction pointed out, I now address myself in the hope of rendering their studies of the naked-eye appearance of healthy and diseased brain more inviting and instructive, by means of a few simple directions as to what appearances are to be sought and how they are to be looked for. A few fiu-ther statements on the object and scope of these articles may not prove amiss. I address myself almost exclusively to the student who, up to the present time, has devoted but little of his attention to cerebral pathology or to the histology of the central nervous system ; and more especially to asylum medical officers, whose opportunities for research in this field are so numerous, yet so sadly neglected. I shall endeavour here to place at the disposal of the student the more important, essential, and trustworthy information in this department which I find scattered promiscuously throughout an extensive literature. If amongst these gleanings my remarks should appear to the advanced student burdened by too much detail, my excuse must be that the primary object is to overcome the diffi- culties presented by these studies to the novice, difficulties which every expert observer has at the beginning to encoimter. PAET I COARSE EXAMINATION OF THE BEAIN U« CHAPTEE I. THE DURA MATER AND VENOUS SINUSES. General Anatomical Features, — It is necessary here that the student should recall to mind certain anatomical details affecting the relationships of this membranous investment of the brain which have an important pathological significance, and in the first place note that : — 1. The dura mater is a fibro-sevous membrane ; the outer sm-f ace being fibrous and rough, the inner being smooth and polished by a layer of epithehal cells constituting a parietal arachnoid. 2. Cut off a small portion and float it in water. The rough pilose outer surface due to the numerous fibrous connections and vessels which unite it to the inner table of the skull becomes hereby very apparent in contrast to the smooth inner surface. 3. Next note that the dura mater is composed of Uco didinct layers, which, by their divergence, occasion the formation of the different venous sinuses ; whilst the inner layer, by its duplications, forms the various intra-cranial membranous partitions, the falx cerebri and cerebelli, as well as the tentorium. 4. Lastly, he must observe the close anatomical relation- ships between the lateral sinuses and the mastoid cells, and again between the superior petrosal sinuses and the internal ear. Caries of the petrous portion of the temporal bone and of its mastoid cells is so frequent an affection, that the con- tiguity to them of tliese venous sinuses is most important as 1! 2 4 COARSE EXAMINATION OF THE 15RA1N. likely to occasion not only localized pachymeningitis or inflammation of the opposed dura mater, but inflammation and thrombosis of the venous siniises, leading probably to metastatic deposits in the lung. 5, The position of the vense Graleni, which receive the blood returning from the choroid plexuses and open into the straight sinus, is such that tumours or abscesses of the mid- lobe of the cerebellum would compress them. Upon removal of the skull-cap the student should proceed to investigate the condition of the dura mater after the follow- ing systematic manner : — 1st. Note the general aspect of the membrane covering the hemispheres. 2nd. Examine the several venous sinuses. 3rd. Observe the condition of the dura mater in those regions at the base Avhere there exists a special proclivity to disease. General Appearance at the Vault. — A glance at the superficial aspect of the dura mater may reveal the presence of inflammatory products which are frequent here. If present, note their character, whether they are simple inflammatory exudates, capable of undergoing organization, or whether they be the results of suppui'ative inflammation. In the former case, observe how softened the membrane is, and how readily separable from the bone ; in the latter case the presence of pus will almost certainly lead to the detection of a carious state of the internal table and diploe of the skull, and a more or less sloughy aspect of the disintegrating mem- brane. The organizable • blastema maybe found in various stages of development, as loose areolar or thick tough fibrous tissue, or it may have formed bony plates which eventually unite with the cranial bones. Should dense fibrous bands be formed, adhesions betwixt the dura mater and bone occur, chiefly along the course of the sutures, or in localized islets over frontal or parietal bones, or so extensively that it is THE DURA MATER AND VENOUS SINUSES. imj)Ossible to remove the skull-cap without at the same time including the dm-a mater, as their forcible separation would entail injury to the brain. If there be the above given indications on the sm'face of recent or of old inflammation, note the density, thickness, Sicollent appearcowe, and colour of the membrane at these parts. Recent inflammations involve much swelling, interstitial infiltration, softening and looseness of textiu'e, and a very red colour ; whilst the effects of an old inflammation are seen in a callous fibroid induration and thickening, often with bony concretions formed in the interstices of its textm-e, together with the adhesion to the inner table of the skull just alluded to, - The student must be prepared to make allowances for the general increase in thickness and firmer adhesion of the dura mater, which pertains to advanced age independent of in- flammatory changes. Superficial inspection will also enable him to detect attenuation of this membrane, such as results from the pressure of a hypertrophied brain, from the effusion of hydrocephalus or morbid growths. Local thinness of this membrane also may be due to the pressure of pacchionian bodies which perforate the dm-a mater frequently, and imbed themselves in fossae on the internal surface of the cranium. Extravasation of blood, forcing the membrane apart from the bone, may be frequently found, and its origin should be carefully sought. Examination of the larger Venous Sinuses. — A fold of dura mater close to the longitudinal sinus at its exposed frontal extremity must now be pinched up by a forceps, and the scalpel passed through it and do^vn into the longitudinal fissure of the brain, so as to divide the union betwixt the falx cerebri and crista galli. Introduce a curved bistoury into the anterior end of the longitudinal sinus, and carry the blade backwards to its occipital extremity so as to expose the sinus throughout its greater extent. The oblique orifices of 6 COARSE EXAMINATION OF THE BRAIN. the veins of the vertex which empty themselves into this sinus mil now be exposed. Note, 1st, The capacity of the sinus throughout. Note, 2n(i, The nature of its contents. Note, 3rd, The condition of its lining membrane. The incision through the frontal end of the falx cerebri should now be extended on either side through the dm\a mater backwards, upon a level with the sawn edge of the cranial bones. The anterior extremity of the falx being then seized with a forceps, should be drawn forcibly backwards from between the hemispheres, carefully dividing the great superficial veins where they open into the sinus, when the convolutionary aspect of the brain, covered by its soft mem- branes, will be exposed to view. At this stage of dissection the pia mater, arachnoid, and superficial aspect of the brain will require attention, and the method to be adopted will be detailed in the following chapter, to which the student must be referred. Continuing, however, our examination of the sinuses of the dura mater, it must be presumed that the brain has been removed, and the following procedure will then be necessary : — Lay open the larger venous sinuses at the base, commenc- ing at the torcular herophili behind, and carrying the blade down eacli lateral sinus to the foramen jugulare. Open up the straiglit sinus running into the torcular herophili in the base of the falx cerebri. Deal in like manner with the petrosal and cavernous sinuses. A close inspection of these sinuses should be instituted with the object of learning the natiu'e of their contents, and the morbid or healthy condition of the textm-es of these venous channels. The most frequent morbid conditions foimd here are those of phlebitis and thrombosis, the thi^ombus being usually the result of inflammation of the walls of the sinus. Thrombosis of the venous sinuses of the dura mater is so frequent and so important an affection, that the possibility of THE DURA MATER AND VENOUS SINUSES. I its occurrence should always suggest itself when examining this membrane. If a thrombus obstruct any one of these sinuses, note the more or less organized condition of the clot and its adhesion to the lining membrane of the sinus. Examine closely its apparent site of origin and extensions, the latter often reaching into the jugular veins. Next take into consideration the constitution of the clot, whether recent, organized and firm, or breaking up and pre- senting the appearance of a crumbling mass, which, dming life, would give rise to metastatic deposits in distant organs. The condition of the lining membrane and tissues of the sinus should next be noted. If inflamed, the inflammatory action should be traced to its origin, usually in a carious state of the cranial bones ; or by extension of simple inflam- mation of the dura mater in the neighbourhood of the sinus ; or less frequently, induced as a secondary resvdt of thrombosis. The student should carefidly study the effect of plugging of the different sinuses, and their proclivity to disease as a result of their varied anatomical relationships. 1. Inflammation of the longitudinal sinus will be accom- panied by occlusion of the venous trunks from the convexity of the brain where they open into the sinus. 2. If the straight sinus be occluded as the result of adhesive phlebitis, the student will remark that its effects in obstruct- ing the return of blood from the choroid plexus will be similar to what occiu-s when the venae Graleni are compressed by a tumour of the mid-lobe of the cerebellum. Effusion into the ventricles might be expected in these cases, and the enlargement of the head from this cause has been recognized clinically. 3. If the lateral sinus be inflamed, we miglit expect, as a result, extension of phlebitis into the jugular veins, and plugging of the smaller sinuses or veins opening into it. In connection with this — note, that the small " emissary veins " (Santorini), which perforate the bone at the anterior extremity of the lateral sinus, and Avhich form a communication between 8 COARSE EXAMINATION OF THE BRAIN. tlie sinus and tlie veins on the outside of the skull at the back of the head, may become plugged by a thrombus producing a painful a3dema behind the ear, also recognized clinically by Grriesinger.^ 4. The position of the petrosal and lateral sinuses naturally exposes them to phlebitis and thrombosis. Lying on the petrous portion of the temporal bone, they are always liable to be implicated by extension of inflammation from the internal ear and caries of the temporal bone. 5. Thrombosis of the cavernous sinus has been frequently noted. In connection with this condition the student must be prepared to note the pressure which will probably result to the carotid artery, which runs through this sinus invested by its lining membrane." He may also look for extension of inflammation of the coats of this sinus to the facial veins with which the ophthalmic vein communicates, noting the obstruction to the return of blood from the cavity of the orbit. 6. Amongst other results of thi'ombosis of the cerebral veins and sinuses, will often be found punctiform hasmor- rhages into the substance of the brain. General Appearance at the Base. — Observe the con- dition of the dura mater at the base, where there exists a special proclivity to disease. The sites alluded to are : — 1. Petrous portion of temporal bone. 2. Ethmoidal plate. 3. Parts adjoining superior cervical vertebrae. 1 Quoted by Niemeyer in " Text-Book of Practical Medicine," vol. ii. 2 This condition has been recognized clinically by a loud bruit heard on auscultation of the skull. Dowse, etc. Lancet. CHAPTER 11. THE ARACHNOID AND PIA MATER. General Anatomical Features. — In proceeding to in- vestigate the healthy and morbid appearances of the arach- noid, the follomng anatomical facts will prove serviceable to the student. 1. The arachnoid is usually regarded as consisting of a parietal and visceral layer like ordinary serous sacs, the former, however, being merely a layer of nucleated poly- gonal epithelium lining the inner surface of the dura mater ; the latter forming the far more substantial invest- ment of the convolutions of the brain separated from them by the pia mater. This closed sac is lubricated by a portion of the general cerebro-spinal fluid. 2. The visceral layer of arachnoid does not dip into the sulci with the pia mater, but bridges them across, whilst in other regions it is widely separated from the pia mater so as to enclose between them extensive spaces. Thus, at the base, a delicate veil of arachnoid stretches across the pons and interpeduncular space as far as the optic chiasma ; a similar film of arachnoid closes in the fouiih ventricle, stretching across from the medidla to the cerebellum ; the arachnoid also does not pass down to the bottom of the longitudinal fissure, but spans across immediately beneath the falx cerebri ; hence a space is left here between the two inner membranes of the brain immediately above the corpus callosum. 3. The various spaces alluded to above all communicate freely with one another, and with an extensive space around 10 COARSE EXAMINATION OF THE BRAIN. the whole length of the spinal cord betwixt the pia mater and arachnoid sac. The whole system of spaces is termed the subarachnoid space, and is filled by the greater bulk of the cerebro-spinal fluid. 4. A space intervenes between the parietal layer of the arachnoid and the dm-a mater. It has been fully investigated and described by Axel Key and Ketzius/ and is called by these anatomists the sub-dura-mater space (subdiu-alraum). The student must therefore regard the membranous invest- ments of the brain as consisting of a lirm and immovable fibrous outer membrane, the dm'a mater forming also the periosteal lining of the cranial cavity ; of an intermediate serous sac or arachnoid whose visceral layer moves freely with the movements of the hemisphere ; and lastly, of a vascular membrane supporting the blood-supply of the brain — tlie pia mater, which closely lines the cortex, dipping into the sulci, and being prolonged into the ventricles. Between the various investments are fom* great cavities : — 1. The subdui'alraum betwixt diu-a mater and the parietal arachnoid. 2. The arachnoid cavity formed by the arachnoid sac. '3. The sub-arachnoid cavity betwixt visceral arachnoid and pia mater. 4. The epi-cerebral space betAvixt pia mater and cortex. It must also be borne in mind that compensatory adjust- ments for lessened or decreased intra-cranial pressure are obtained by means of the cerebro-spinal fluid ; increase in the pressure, as in the increased amount of blood, gro-sHh of tumours, etc., being allowed for by escape of this fluid into the spinal sub-arachnoid space. In relation to this important subject it has been shown by Axel Key and Eetzius, that the pressm-e of the cerebro-spinal fluid is always higher than that of the venous blood, and its specific gravity lower ; hence its ' "Studieu in der ADatomie des Ncrvensystems." Axel Key und Gustav Retzius. Stockholm, 1875. THE ARACHNOID AND TIA MATER. 11 free mingling with the blood-currents by osmosis is much facilitated.^ Coarse Examination of the Membranes. — The healthy and morbid appearance of the arachnoid should be subjected to close and critical examination. Upon reflecting the dura mater the contents of the arach- noid sac will be revealed, and in relation to this point we must note : — 1. Variations in the amount of cerebro-spinal fluid here. 2. Modified appearance of this fluid from admixtm-e with morbid products. 3. Note especially extravasations of blood, and the age of these haemorrhages as revealed by the condition of the clot. It may be purely fluid blood, coagula, or a delicate film of fibrinous nature ; or it may be in various stages of organiza- tion. The various stages of the arachnoid cyst in relation to pachymeningitis have all been most graphically described. 4. Note the superficial aspect of the visceral and parietal arachnoid as regards — a. Absence of clear, moist, glistening surface. h. Presence of morbid deposits, such as films of lymph of varied appearance and stage of organization ; as a delicate, greyish, mucus-like exudation, or a mem- brane possessing a certain amount of consistence, or flakes which are yellow and pimform, and more rarely fibroid patches ; or, again, the development of bony plates in the parietal layer. c. Adhesions between layers of arachnoid sac, such as occm' naturally by the development of the pac- chionian bodies. 5. Note the anomalies of texture due to interstitial change and to deposits occurring here. The effect of frequent hyper- ' Op. fit. 12 COARSE EXAMINATION OF THE BRAIN. reiiiia is seen in tlie opalescent, creamy white, or perfectly opaque appearance presented, especially along tlie course of the blood-vessels, and always seen after middle life to a greater or less extent. Hypertrophy of the textures, giving the membrane a tough and thick character, will result from similar causes. The membranes may be, however, soft, tumid, and swollen from cedema of its texture ; and where it bridges the sulci a solid gelatiniform aspect is often given it by the subjacent fluid. 6. The relative amount of cerebro-si:)inal fluid in the sub- arachnoid space should next be taken into account. It should be collected, together with that which escapes from the arach- noid sac and ventricles, and carefully measiu'ed. The appear- ance of the arachnoid, when buoyed up by any undue amount of this fluid, should be noted before removal of the brain from the skull. It will be found that in these cases the arachnoid is widely separated from the pia mater by the sub- jacent fluid. The limpid character of this fluid may be tested by slitting up the arachnoid over a sulcus. So far our remarks chiefly apply to the arachnoid, and we will now turn our attention to the pia mater. The proximity of these two membranes to one another of course predisposes to their common implication in any morbid process, yet the pia mater is not by any means unusually involved without extension to the brain-substance, and still more frequently without extension to the arachnoid. In healthy states these membranes are very thin and delicate, and removed from the brain-surface with difficulty. "We should, therefore, note their proximity to each other over the summits of the gyi'i, alterations in the thicliness of the pia mater and in its toughness, infiltratimis of its texture, and the ease or difficulty experienced in its removal from the cortex. Thus it may be found widely separated from the arach- noid, the latter being buoyed up by sub-arachnoid effusion. In these cases the appearance of the fluid should be noted, especially as regards the presence of inflammatory exudates, as flakes of lymph, etc. THE ARACHNOID AND PIA MATER. 13 If thickened in textm-e the alteration of the pia mater should be traced to its origin, whether this be simple serous infiltration or oedema conjoined with inflammatory material. Tortuosity and varicosity of the vessels will also be further indications of repeated congestions of this membrane. Espe- cial caution must be observed against drawing hasty conclu- sions regarding congestion of the membranes from the mere fulness of the blood-vessels and hypostasis.^ The student will find ample opportunity for studying the appearances presented by oedema and thickening of the soft membranes of the brain in cases of senile atrophy, general paralysis, and alcoholism. The presence of inflammatory material modifying the thickness and toughness of the membranes should lead to a study of the nature of the exudate, whether it appears as a tough exudate of plastic lymph more or less yellowish in hue, or more serous, sero-purulent, opaque, and less organ- izable material. With the presence of these more or less plastic exudates note the general infiltration of the membranes around with greyish, opaque serum. Such changes afford excellent opportunities for the study of the results of inflammatory action in loose areolar tissue. In connection ^vdth inflamma- tion of the pia mater — a condition which will frequently engage the attention of the student — he should also follow up his investigation of the nature of the exudate by examining also : — a. The direction taken by the morbid product, noting that this occiu-s almost invariably along the vas- cidar tracts, the coiu'se of the vessels being marked out by opacities. h. The extension to neighboming structm-es (brain, arachnoid, dura mater, and skull). c. The limitation of inflammation to s)naU areas (as when originating secondarily from caries of the ' On this point see Niemeyer. Art. " Hyi^ersemia of Brain and its Mem- branes." "Text Book of Medicine," yoI. ii. 14 COARSE EXAMINATION OF THE BRAIX. cranial bones) ; or to the coiivexifij of the hemi- spheres (chiei3y accompanied by plastic products) ; or, lastly, characterized by the base of the brain being originally and chiefly involved (usually accompanied by aplastic and tubercular pro- ducts.) Note attentively the greater or less facility of stripping the pia mater from the cortex. The membrane may be oeclematous, thickened, gelatinous, and most readily removed ; or, on the other hand, it may cling with greater tenacity or adhere so firmly that portions of the cortex tear away with it, leaving an eroded, worm-eaten aspect of the surface of the gyri. Attention should be directed to the strength of these adhe- sions, their implication of the summits of the gyri only, their localization over the convolutionary surface of ihe brain, and the coarseness of the blood-vessels entering the cortex at the sites of adhesion. Whenever the student is engaged with a case of menin- gitis, the morbid topography must be carefully studied. If basic, the veil of arachnoid extending from the optic chiasm to the pons must be examined and removed, noting imjolica- tion of the numerous vascular and fibrous twigs extending betwixt it and the subjacent pia : follow these results of inflammatory action up along the vessels of the fissures of Sylvius and the anterior cerebrals in the longitudinal fissure. Examine the regions just named for tubercular granulations, paying especial attention to the smaller blood-vessels, which may have tubercular masses in their sheaths, occluding more or less the calibre of the vessel. Should granulations appear around the blood-vessels, let them be removed and floated in water for more careful observation. CHAPTEE III. ARTERIAL SYSTEM OF THE BRAIX. Dissection. — After carefully noting the external appear- ance of the membranes covering the hemispheres both at the vertex and the base, the condition of the arterial system should be inquired into. The brain being placed with its base uppermost, the fine expanse of arachnoid which bridges across the inter-peduncidar space is first removed, and the great vessels forming the circle of Willis will then be ex- posed to view. Now separate the temporo-sphenoidal lobe from the adjacent frontal and parietal lobes by di\'iding the bridge of arachnoid extending between them across the Sylvian fissure. On gently drawing back the temporo-sphenoidal lobe the Sylvian branch of the middle cerebral artery will be observed running deeply in the fissure towards the upper extremity of the latter, giving off small branches in this coiu-se. The radiating gyri of the island of Reil (central lobe) vnW in most cases be only partially exposed, and it will be necessary to separate the opercuhmi, or that portion of the third or inferior frontal convolution which laps over the anterior portion of this lobe. The five or seven gyri of the island will now be seen radiating outwards like a fan and supporting the various branches deri-\-ed from the middle cerebral in its sulci. Split up the arachnoid which bridges across the longi- tudinal fissure anteriorly from one frontal lobe to the other. We shall thus have exposed the various branches of the circle of Willis as far as they can be seen at the base. Note first the arrangement of the blood- ve!<!<eh. 16 COARSE EXAMINATION OF THE BRAIN. The Circle of Willis. — A first glance at the arrange- ment of the great arteries at the base of the brain entering into the formation of the circle of "Willis cannot fail to impress upon the student's mind this important fact : there are here two great arterial systems more or less distinct and inde- pendent. In front lies the carotid system, supplying by far the greater bulk of the brain ; behind lies the vertebral system, distributed to the posterior and inferior regions of the cere- brum — an area small in comparison to the former. These two great arterial systems are united by the two posterior comnumicating arteries which connect each carotid with its corresponding posterior cerebral artery. Examine the posterior communicating arteries and note the remarkable smallness of their calibre, a fact which suffices to ensure us that the circulation in the carotid and vertebral systems is in the main distinct; whilst the arrangement allows of compensatory enlargement and a free communica- tion betwixt both systems where emboli, thrombi, or diseased textures obstruct the circulation of a main branch. Next observe the junction between the two anterior cere- brals deep in the longitudinal fissure by means of the cross branch, the anterior communicating artery. Raise the branch on the forceps and note its short length, small calibre, and right-angled direction, facts which teach us that, although in case of obstruction on the carotid side of the anterior cerebral, this branch, by dilating, may afford a satisfactory re-establish- ment of circulation over the area to which it is distributed, yet for the greater part the circulation betwixt the two anterior cerebrals is distinct. A little further consideration will teach us that the circu- lation of each hemisphere is by the above mechanism rendered wholly distinct and independent ; that the circulation of the mid-cerebral region of one side is wholly separated from that of the opposite hemisphere ; whilst the anterior cerebral areas are more closely associated through the medium of an anterior communicating branch. Lastly, through the medium of tlie posterior communi- ARTERIAL SYSTEM OF THE BRAIX. 17 eating artery (especially when we recall to mind the frequent enlargement of this vessel met with) there will be a far more ready communication betwixt the carotid and vertebral cir- culation than there can be betwixt the vascular apparatus of both hemispheres. We should pay especial attention, there- fore, to the following observations : — a. The almost comj)lete independence of hemispheric circulation. h. The very complete independence established betwixt the circulation of one middle cerebral and that of the other. c. The interdependence established betwixt the two anterior cerebral streams through the medium of an enlarged communicating branch. d. The possible admixture of the carotid and vertebral circulation of the same side through the medium of the posterior communicating — a condition very frequently established. The arrangement of the internal carotid ere it reaches the circle of Willis is one of interest and significance. Within its bony canal the tortuous sigmoid com'se taken by it is undoubtedly one means whereby the brain is protected from the results of the cardiac pulsations. The student will recall a similar tortuous course taken by the vertebral artery ere it enters the cranium. It has long been noticed that the middle cerebral is more readily blocked by emboli than the other branches, and that the area of its distribution shows especial proclivity to haemorrhage. Anatomical reasons, and the fact that this vessel lies " more directly in the way of strain fi'om the heart explains its frequent plugging and ruptui-e from disease " (Hughlings Jackson ^). Thus Prevost and Cotard found that tobacco seeds injected into a dog's carotid most often lodged in the middle cerebral. Again, the fact that the left carotid arises directly from the summit of the aortic arch, whilst the right, arising from the innominate, > Lancet, September 4, 1875. (; ^'5 18 COARSE EXAMINATION OF THE BRAIN. is inclined at an angle to the aortic current, is sufficient to explain the greater immunity from embolism experienced by the right carotid in its distribution to the brain. The right vertebral arises from the horizontal part of the subclavian, and is therefore also less subject to embolism than the left vertebral, which arises from the simimit of the ascending portion of the left subclavian. The Arterial Tunics. — Note the following points : — 1. Colour and opacity. 2. Relative toughness of coats. 3. Tortuosity or kinks in the course of the vessel. 4. Local bulgings or constrictions from diseases of texture. 1. The arteries may be perfectly white in cases of slow and lingering death, and contain a decolourized clot extend- ing into its minute ramifications. On the other hand, they may be of a deep red hue from fluid blood, dark clots, and blood staining of the lining membrane. The vessels, again, may be thin and semi-transparent, or opaque from thicken- ing of the arterial tunics and morbid deposits. 2. The toughness of the arterial tunics caji be tested later on after their removal. Their resistance to strain is an im- portant feature, and due attention should be paid to it by the student. The apparent thinness of a vessel should never be allowed to deceive him, as the thicker vessels are often most degenerated and least resistant to traction or expansion. Traction may be applied to the vessel held between two pairs of forceps, when an approximate idea of the breaking strain may be acquired, whilst the use of a conical gauge will enable him to note the various degrees of resistance these textures offer to expanding forces. 3. Tortuosity and kinks in the smaller branches should be noted as suggestive of previous forcible distension from con- gestion. This is often apparent in the larger arteries ; thus, Quain has noticed frequent tortuosity of the internal carotid before it enters the carotid canal outside the skull in apoj^lec- tic subjects. ARTERIAL SYSTEM OF THE BRAIN. 19 4. Local biilgings may be clue to aneurismal dilatations, to the different forms of arteritis— atheroma, tubercle, syphilitic gummata, or to the impaction of a thi'ombus or embolus. The arteries at the base mil be found often exceedingly atheromatous, tortuous, knotty, and white ; the amount of atheromatous material occluding even the larger cerebral arteries, often converting the smaller branches into irregular knotty cords. The student should never infer from the aspect or feel of such a vessel that it is occluded, but he should always make a section across the mass of diseased tissue, when, if the vessel be permeable, the orifice is readily detected. Note particularly the branches which are occluded. If the bulging be due to inflammatory swelling and exudation into the outer tunics of the artery, it will be observed that corresponding to the site of lesion the vessel is dilated — a condition due to paralysis of the muscular coat of the vessel, together with implication of the elastic outer timic. Make a section across the inflamed tissue, and observe how readily the elastic or outer coat may be stripped from the muscular by means of a forceps ; also how friable and easily separable are the muscular fibres of the media. The inner coat mil be probably deeply stained by htematin, or may be eroded and covered by an adherent clot immediately beneath the inflamed patch. When a clot appears to obstruct the calibre of a blood-vessel, the character of the clot should be taken into consideration, its fibrinous constitution, stage of organization, adhesion to vascular walls, its fomi, prolongations, and appearance of its section. The sheath and outer tunic of the arteries should be closely examined, especially in the neigh- bom^hood of the Sylvian fissure and island of Reil, for tuber- cular or syphilitic growths. Especial care must be taken to exactly note the arterial tunics involved, so as to discrimi- nate between ordinary endarteritis, residting in atheromatous degeneration, and the syphilitic node or gumma involving the outer coats, and the tubercular nodules involving the arterial sheaths, all of which lesions may give rise to blocking, con- 20 COARSE EXAMINATION OF THE BRAIN. traction of the cavity, and thrombosis. Such lesions should he examined microscopically. In all cases the above super- ficial examination should be supplemented by removal of short lengths of any diseased vessels, to be reserved for freezing and section-cutting, according to the methods detailed in the microscopic section. The vessels spreading over the island of Reil and up the Sylvian fissure should now be raised by passing a forceps beneath them, and with a clean sweep of the scalpel they should be all divided just where they turn over on to the superficial aspect of the brain ; this should be repeated on the opposite side. The two anterior cerebral arteries should now be divided at the genu of the corpus callosum, and dissected back to their origin from the carotids. The posterior cere- brals will be found running backM^ards round the crura cerebri under cover of a bridge of arachnoid. The posterior cerebrals, together with the three cerebellar branches, may be followed to a short distance and then divided. It will now be found that the circle of Willis is retained merely by the numerous minute nutritive branches, between the basilar artery and pons, and those from the anterior, middle, and posterior cerebrals, which pass through the anterior and pos- terior perforated sj)aces. Grently draw these vessels out by means of a forceps as far as possible, sever them close to the surface of the brain, and then float off the vessels of the base into a shallow dish or plate of water, arranging the branches in their relative positions. Capacity of the Arteries at the Base. — It may be found advisable in certain cases to test the relative capacity of the larger vessels at the base, and this may be obtained approximately by means of a small graduated conical gauge. In making these comparisons the student should bear in mind that the united areas of the branches equal very nearly the area of the trunk from which they originated, although their united diameters far exceed that of the latter. It has been shown by Paget's measurements that the equality ARTERIAL SYSTEM OF THE BRAIN. 21 between the area of the trunk and of its branches is not exactly maintained, the area sometimes increasing in the vessels of the upper extremities and head and neck, and diminishing in the lower extremities. Now, according to the mathe- matical law that the areas of circles are as the squares of their diameters, it will be necessary to contrast in our measurements the square of the diameter of the trunk with the sum of the squares of that of the branches arising from it. The student, therefore, should proceed in the following manner : — Let us suppose he wishes to estimate the relative capacity of the vessels at the base and theii' primary branches ; let him remove these vessels as already recommended, and float them out in a shallow vessel containing water. With a sharp pair of scissors cut across the vessel exactly at right angles to its direction, pass the graduated cone into it, and gently draw the vessel on until it is fully distended, but not stretched, by the gauge ; read off the diameter as shown on the gauge, and proceed in like manner mth the other vessels. Arrange the diameter and the squares in appropriate columns, opposite the names of the vessels, for future comparison. The following tables represent the average measurements of the various vessels at the base in forty-five cases of insanity I have investigated : — DiAMETEB. Vertebral Artery — Right Left Basilar Posterior Cerebral —Right Left Carotid — Right . . . „ Left .... Mid- Cerebral— Right . Left . . Anterior Cerebral — Right Left mm. 147 Square. 42 82 658 56 951 02 133 55 73 66 10 12 14 7 6 15 16 10 10 7 7 •J41 •039 •805 •213 •551 •789 •026 •063 •;.^5i •55 •■145 22 COARSE EXAMIXATIOX OF THE BRAIN. Thus the sum of the square of the diameters of the anterior aud middle cerebrals of the right side was to that of the left side as 17-613 to 17-796. The square of the diameter of right and left anterior and middle cerebrals amounted in the aggregate to 35-409, both posterior cerebrals reaching only 13-764. Contrasting again the mid-cerebral supply of both sides with that of both anterior cerebrals, we find it represented by 20-414 against 14-995. Reference to the table of measurements will show that the posterior and anterior cerebral supply of both sides is almost exactly similar : thus, on the right side, we find 7-213 con- trasted with 7-55 ; and on the left side, 6-551 with 7-445. Another interesting feature in connection with these measurements is the great preponderance in areas of the two vertebrals over the basilar, which they form by their union. The two former have as the sum of the square of their diameters 22*38, the basilar only averaging 14-805 ; and in several cases I have found the basilar artery not more than one-half the area of the united vertebrals. It may assist the student to obtain a clearer idea of these areas if he represents them graphically as straight lines upon an enlarged scale. Vessels of the Pia Mater. — First note the general appearance and distribution of the vessels of the pia mater as they lie in situ. Observe the relative position taken by the veins and arteries, the former being large and sujierficial, the latter much smaller and concealed chiefly within the folds of pia mater, which dip into the sidci and are bridged across by arachnoid. The upper aspect being arachnoid, should, in health, present a smooth endothelial surface. Use a hand-lens in examining these vessels. The student should observe any fibrinous effusions, purulent exudates, or minute extravasa- tions along the course of the blood-vessels, the presence of atheroma, morbid growths — as gummata, tubercle, etc. If tuberculosis be suspected, examine the arteries deep in the ARTERIAl, SYSTEM OF THE BRAIN. 23 sulci, and this with care, as tubercle along the course of the vessels is found with far greater difficulty here than at the base or up the Sylvian fissure. Next strip off a large portion of arachnoid and pia mater from the sm-face, and transfer it to a deep vessel containing water, the arachnoid siu"face being uppermost. Observe the velvety aspect of the lower surface, due to a fine pile of blood- vessels, and the very rich fringe of vessels along the inter- gyral folds, for the supply of the cortex deep within the sulci. Seize Avath a forceps one of these richly fringed folds and snip off a portion with a scissors, floating it on to a glass slide, with its vessels disentangled and spread out. Eemove also to another glass slide a portion of the membranes de- tached from the summit of a convolution, and study them by means of a hand-lens, both in reflected and transmitted light. Educate the eye in this manner to the recognition of the various healthy and morbid structures to be found here. For microscopic purposes, both these slides last mentioned should be reserved, whilst a small portion of brain covered by its membrane, and including two adjacent convolutions, should also be set aside. These will aiforcl subjects for a hrnVs-eye view of the surface under low powers of the micro- scope, such an examination being always insisted upon as especially valuable. The portion of brain must then be frozen and cut in such a direction that the sections so obtained represent both gyri with the intervening sulcus bridged over by arachnoid. We thus obtain very beautiful slides for fresh examination, which afford us the opportunity of minute examination of the cortex and the connections and relation- ships between it and its membranes. The large superficial veins at the vertex where they open into the longitudinal sinus, are occasionally found plugged by thrombi ; they shoidd therefore always be examined with the object of ascertaining the nature of their contents, espe- cially if there is evidence of inflammation of the dura mater or its sinuses, or of pm-ulent meningitis. The student should also take CA'ery opportunity of follow- 24 COARSE EXAMINATION OF THE BRAIN. ing up the arterial branches given off from the anterior, middle, and posterior cerebrals, in their course along the sulci, until he has familiarized himself with the exact supply of various regions and convolutions of the brain. It is only necessary to allude to the work of Duret and Charcot in this direction to indicate the importance of a minute knowledge of the arterial districts of the encephalon in order to fully appreciate numerous lesions met with in the brain. Nutrient Vessels at the Base. — We should devote attention to the numerous vascular tufts which arise from the large vessels at the base for the supply of the central ganglia and pons Varolii. Those which supply the basal ganglia are disposed into anterior and posterior groups — the former arising from the anterior cerebral, anterior communicating, and middle cerebral ; the latter taking origin from the bifur- cation of the basilar, often from an enlarged posterior com- municating, a further series arising from each posterior cerebral artery as it mnds around the crura cerebri. Roughly, it may be stated that the anterior group supplies the corpus striatum and anterior extremity of the thalamus opticus, whilst the posterior group is distributed chiefly to the thalamus. Note, first, their remarkably fine calibre, considering their direct origin from main arterial trunks ; and secondly, observe that they are given off from these trunks at a right angle — a significant fact, as they can only be affected to a minimum degree by the propulsive wave of blood caused by each cardiac systole. They are filled, therefore, by a sustained lateral pressm*e. An examination of the nutrient supply to the pons will impress us with the follomng facts : — a. The nutrient twigs arising from the main artery are remarkably small, as in the other cases. h. They also arise at right angles from the basilar. c. The basilar is but slightly over half the capacity of both vertebrals, which supply it. ARTERIAL SYSTEM OF THE BRAIN. 25 The latter fact, which I have abeady demonstrated by measurement in our remarks upon arterial capacity, when taken in conj unction with the other two data, warrants us in assuming that these nutrient branches are kept constantly filled by high lateral pressure, and exhibit none of the phenomena of the pulse. I need not insist upon the beauty of this arrangement of means to end. In removing the vessels at the base, be careful not to tear these nutrient vessels short, but with gentle traction draw them out and cut them across with fine curved scissors ; float the circle of WilHs and its branches in a shallow dish of water, and examine the various nutrient groups. Snip off some of the anterior and posterior tufts, float them on to a slide, arrang- ing the branches, and examine by the naked eye as well as by microscopic aid. Wherever arterial degeneration is suspected, never miss the opportunity of thus closely inspecting the nutrient supply of the corpora striata, optic thalami, and pons Varolii. The naked eye will sufiice to reveal to us aneurismal dilatations along these branches, atheromatous degeneration, thrombi or embolic plugging, often explanatory of haemorrhages within the structure of the basal ganglia or pons. CHAPTER IV. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. In the introductory chapter to his great work on Pathological Anatomy, Rokitansky has said : — " Just as there is a general and a special anatomy, physiology, pathology, so there must in like manner he a general and a special pathological anatomy. The former treats of anomalies of organization, the latter of the special anomalies of individual textures and organs.^ " It appears to me that in the examination of the diseased brain this natural classification must be kept in view. The student should be taught to appreciate the various general anomalies of organization as they present themselves in the brain ; and the methods to be adopted in estimating the degree, extent, and significance of such physical deviations. It is, of course, not our function to detail the various diseases of texture to which the brain is subject, but rather to place the student in possession of those indications of healthy and diseased tissues which are presented by alterations in the physical properties of grey and white matter. The elements of a physical diagnosis, so to speak, are placed at his disposal, and hints thrown out for his guidance, where it is thought a wrong construction might be attached to the physical signs. It will be found convenient, however, to illustrate the more profound anomalies in consistence, colour, specific weight, and other physical qualities by reference to some of the i^pecial diseases of texture to which the nervous centres are liable, and ' "Pathological Anatomy," Sydenham Soc. vol. i. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 27 which may serve as typical eases wherein the student may acquire a practical acquaintance mth the methods of pliysical research. The fundamental physical properties of the nervous tissues with which it is necessary we should acquaint ourselves are briefly as follows : — Consistence, colour, volume, and weight, both absolute and specific. Each in turn will now claim our close attention. § CONSISTENCE. The firmness, solidity, or consistence of a textm^e depends upon the cohesive force exerted by the individual elements of its mass, and to which is due, on the one hand, the varying degrees of toughness, hardness, and resistance, or, on the other hand, of softening and friability and liquefaction, to which they are liable. The consistence of a compound tissue so complex as the brain is necessarily subject to very great variations, since its individual constituents vary amongst themselves greatly in their physical properties. An organ composed of nerve-tubuli, nerve-cells, of a connective frame- work, and an elaborate system of arteries and veins, the whole pervaded by nutrient fluid, must be subjected to great modi- fications in consistence due to alterations in the relative pro- portions of one or other of the constituents. Hence it is that we get such variety in the structural firmness of brain- tissue, not only in different animals and in the brain of man, but in different regions of the same brain. It is this textiu^al difference betwixt grey and white matter which explains their varying degrees of consistence, the same explana- tion pertains to the firmness of the occipital as contrasted with the frontal lobe, and of the central grey ganglia as con- trasted ^\ith the grey envelope or cortex of the cerebrum. The grey cortex, consisting of a vast assemblage of nerve- cells and their protoplasmic extensions, imbedded in a most delicate web of connective tissue, with a complicated vascular apparatus, has a far lower degree of consistence than the 28 COARSE EXAMINATION OF THE BRAIN. white matter which owes its solidity to large meduUated nerve-fibres and an abundant and coarser connective matrix. A moment's consideration will suffice to indicate that the forces which in disease modify textural cohesion must come from without or from within the structural elements ; in other words, the tissue elements may be forced asunder by fluids pervading the texture and by the intrusion of adventitious bodies, or by nutritive changes in the elements themselves, whereby a quantitative or qualitative transformation may be induced. Conditions modifying Normal Consistence. — 1. The forcible infiltration of nervous texture by serous fluid, by plastic exudates, or by blood, will in the first place tend to destroy all textural cohesion, and consequently produce reduc- tions in consistence ; whilst further changes in the effused blastemata due to organization will result in increased firm- ness or indiu-ation. 2. Chemical changes in the constitution of the individual elements, according to their nature, may tend to produce increase or reduction of consistence, e.g., fatty, amyloid, and calcareous degenerations, the nutritive anomalies due to inflammation, decomposition of the stnictural elements due to putrefactive changes. 3. Apart from the above qualitative anomalies of nutrition, we must not overlook the quantitative element which some- times exists alone or in combination with the former. Such are the forms of hypertrophy and atrophy due to an increase in size and number of constituent elements on the one side, and on the other, in the decrease in size, wasting, and diminution in the number of the tissue elements. The student must guard against the fallacy of regarding density and consistence of a tissue as in any way mutually convertible terms, for although in a large number of cases increased density may co-exist with increased consistence of the brain (sclerosis, hypertrophy, etc.), yet conditions occur where with increase of density there is really a diminution PHYSICAI, PROPEKTIES OF GREY AND AVIIITE MATTER. 29 in consistence. Thus, in inflammatory conditions of the brain-tissue where plastic exudates have forcibly reduced the cohesion of the mass, the specific \iceiglit of the part is notably increased. Hence the specific gravity of cerebral tissue will afford us no exact and reliable guide as to degrees of con- sistence ; and, in fact, we have no more exact gauge of consistence of texture than the rough-and-ready methods afforded by the sense of sight and touch. Estimation of Textural Cohesion. — 1. By the eye we note deviations from the natural compactness of an organ, or the maintenance of its normal contour. Contrast the brain of a senile dement or of a general paralytic with the compact firm brain of epilepsy ; or the same organ in warm weather and in a state of incipient decomposition with the recent brain removed from the skull in cold frosty weather. 2. By the sense of touch note the relative resistance to pressure and the compressible and lacerable character of the tissues. Especially note this with respect to the central com- missural tracts, basal ganglia, fornix, and septum lucidum. 3. By its resistance to a graduated force, such as the rough gauge afforded by a stream of water falling from a variable height (applicable only to cases of much reduced consistence). Any case of white or inflammatory softening may thus be tested. 4. By its resistance to section (applicable to the slighter degrees of reduction and all degrees of increased consistence). Contrast the resistance to section presented by the medulla, pons, cerebellum, cerebral hemispheres, and ganglia at base. Observe that we gain by these means not only a satisfac- tory gauge of consistence, but that the methods vary in their relative value in different cases. We should take every opportimity of rendering oiu-selves perfectly familiar with the general consistence of healthy brain prior to post-moi-tem change. Let us remove a normal brain for careful study, and note the following points : — 30 COAKSE EXAMINATION OF THE BRAIN. The Normal Brain. — Observe that upon removal from the cranial cavity it preserves its normal contour, although it has lost its natural support — the cranial bones. It is plump, rounded, and compact, giving a general impression of firmness and solidity, ere we gauge its consistence further by handling. The hemispheres are closely approximated by means of the strong commissural band — the corpus callosmn, showing no tendency to fall apart from rupture of the commissui-e, such as is so frequently seen in the degenerated and diseased brain. Upon separating the cerebral hemispheres with the hand the corpus callosum appears intact, and offers fair resistance to the blade when dividing the hemispheres along this course. The individual lobes maintain their characteristic forms, their salient margins, and relative positions ; each con- volution remains firm, plump, and in close contact with its neighboui% whilst the arachnoid investment gives a uniform, smooth, glossy aspect to the consolidated organ beneath. A section across the centrum ovale reveals a similar con- dition — observe the general solidity of the parts ; how per- fectly relative positions are maintained ; the absence of any gaping of the sulci ; observe also that the white substance cuts with a clean section, and shows no tendency to cling to the blade. Next open up the lateral ventricles, and observe the rounded firm aspect of the intraventricular portion of the corpus striatum and thalamus. Examine the fornix and septum lucidum — parts especially prone to softening in certain affections of the brain. Pay special attention to the relative consistence and size of the corpora quadi'igemina, the cerebral peduncles, the pons and medulla. Now we must be prepared to meet with all varieties of consistence betwixt the above- described normal firmness of health and extreme alterations produced as the result of disease. The consistence, as we shall illustrate further on, may be so far reduced that the cerebral substance may be perfectly diffluent, and may be poured away like thin cream ; or, on the other hand, it may possess the firmness, aspect, and character of the hard-boiled PHYSICAL PROPERTIES OF GREY AXD WHITE MATTER. 31 white of egg ; or even cause the knife to creak in cutting through patches of almost fibro-cartilaginous induration. Reductions in Consistence. — With the object of ren- dering ourselves familiar with reductions in consistence, let us consider briefly the appearance and significance of those abnormal conditions of cerebral tissue which lead to softening, dwelling only upon those which are most likely to present themselves frequently to om- examination. The conditions best illustrative of reduced consistence are the following : — Putrefactive changes. Softening as the result of disease. a. White softening. b. Yellow or gelatinous softening. c. Red or inflammatory softening. Simple oedematous conditions. 1. Putrefactive Changes. — ^Now these changes in the brain occur sooner or later after death, according to the tem- peratm-e andhiunidityof the surrounding atmosphere, modified, of course, by the morbid conditions of its texture and con- tained fluid. It is on this account that the report of an examination of the brain should invariably be accompanied by a statement of the number of Jwurs offer death at which the examination was made, the average temperature of the post-mortem- room, and the condition of the atmosphere ns to humidity. Fremy, in an elaborate research in 1841 ("Ann. Chim," 2, 463), arrived at the conclusion that the ordinary form of softening of the brain was analogous in its production to the putrefactive process occurring post-mortem ; an opinion which has not been supported by later researches into the chemistry of the brain. We shoidd learn to discriminate between the softening due to this cause, and that due to morbid alteration of texture. We are guided here by observ- ing that the softening is general throughout the encephalon, and attended by much blood-staining from diapedesis, by the evolution of offensive gas, and the presence of the latter 32 COARSE EXAMINATION OF THE BRAIN. within the blood-vessels and beneath the membranes. We must also take into account the absence of any morbid con- dition tending to produce softening, and the conditions, atmospheric and otherwise, to which the brain has been exposed since death. It is essential, also, to keep in mind the fact that various diseases predispose to early putrefactive changes, whilst the mode of death may expedite or defer the same. To retard putrefactive changes when the brain cannot be immediately examined, it shoidd be placed in a cold room with a damp cloth thrown over the hemisphere to prevent desiccation of the outer cortical layers ; or better still, it may be enclosed within an ice safe. The student can readily extemporize for his own use such a safe, by placing the brain in a jar or box which fits into a larger box, leaving a space of an inch and a half around between the outer and inner box, into which ice is packed. The outer vessels must be thickly and completely enclosed in felt. Such a contrivance he will find of great service in the summer months, when it is difficult to keep anatomical subjects fresh for many hours together. Portions of brain reserved for microscopic examination after hardening should be transferred immediately to methylated spirits or Mliller's fluid, or better still to methylated spirits colom-ed of a dark sherry tint by tincture of iodine. For the fresh methods of examination, we must trust to the ice safe for the preservation of om- material, should any delay occur, preservative fluids being scarcely admissible. As regards the latter, however, the strong solution of acetate of ammonium recommended by Sankey ^ is perhaps the best which can be used (sp. gr. r040). 2. Indications of Softening. — A general reduction in the consistence of the brain will usuoUy reveal itself at first sight by a mere superficial glance. The whole brain assmnes an unusually flattened squat appearance, and the hemispheres diverge. The student will find the former due to extension 1 " New Process for Examining Brain Structure," West Riding Asylum Reports, vol. v. p. 192. PHYSK AI. PROPERTIES OF OREY AND WHITE MATTER. 33 of softeuiDg to the central portions of the hemispheres which support in the normal state the convolutionary sm*face folded over them, whilst he observes the commissural band connect- ing the hemispheres (corpus callosiun) tends to split asunder in a longitudinal direction — i.e., across the course of the great bulk of its softened fibres. Proceeding to handle the brain, he finds the convolutions flabby to the touch and presenting less resistance to pressm^e — the whole brain is less able to resist the ordinary force of gravity, and is therefore strongly contrasted with the plump, erect, and compact aspect of the healthy organ. Let the student examine the brain of an advanced general paralytic, and he will find this condition well represented. Cut across the hemisphere of such a brain so as to expose the centrum ovale, and it will be observed that the brain-tissue clings to the blade with unusual tenacity unless the latter be kept constantly wet by water or spirit. As a result, the cerebral tissues, both grey and white, are lacerated and tear away in slireds, leaving an unmistakable softened, rottenecl aspect of the surface of the section. This tearing away of brain-tissue is apt to give one a false idea of the couiparatire coarseness of texfure ; thus, in the brain of a general paralytic the adherent, thickened membrane and softened cortex cannot be cut without leaving a coarse irregular sm'face, unless the precaution be taken of using a very sharp blade, and keeping its siu'face constantly wet. Let us now examine more carefully the special form of soften- ing kno^vn as white softening. 3. White Softening of the Brain. — AVe ma}^ meet with this condition as one generally diffused through a hemi- sphere or in patches limited to a convolution, the area of softening being often no larger than a pea, although more extensive tracts are usually involved. In the fu'st place, suppose we have before us a brain in which the greater part has thus sirffered. The affected hemisphere presents to the touch a soft, boggy feel, sometimes communicating an almost tremulous, fluctuating sensation to D 34 f'OARSE EXAMINATION OF THE BRAIN. the fingers if the disintegration be extreme. The brain will be with difficulty removed, the disintegrated tissue tending to burst through the softened walls which confine it, and more especially is this the case in the neighbourhood of the anterior perforated space and commencement of the Syhian fissm-e. All unnecessary manipulation of such a brain should be avoided, as it is attended with danger to the textural continuity of internal parts, which should also be examined at as early a stage as possible. Observe the lateral divergence of the hemispheres and their flattened aspect above. By gently drawing the hemispheres apart and introducing a blade into the longitudinal fissiu-e, a section may be made outwards across the affected hemisphere, and thus removing the vault we find the centrum semi-ovale occupied by a mass of broken-do"v\Ti medulla — all normal cohesion being destroyed by the presence of a large quantity of interstitial serous effusion. The disintegrated substance will probably have the appearance of soft watery or creamy pap, readily raised upon the blade, or it may be absolutely diffluent, flowing away as soon as the resistance ofPered by the confining grey cortex is overcome. It may, however, retain a certain amount of cohesion, yet break up readily and wash away on placing it beneath a stream of water. The ganglia at the base may be implicated, and the septum pellucidum, grey commissure, fornix, and corpus callosum will generally be found softened or even broken down, the ventricle containing more or less serous fluid. Now such a brain as we have just been con- sidering will be met with in acute hydrocephalus, in tlii-om- bosis, or in embolic plugging of the main cerebral arteries. With such a case before him the student should pay attention to the following points : — a. Degree of softening — Does it resist a stream of water ? Does it render a stream of water milky or break down readily under it ? Is it from the first diffluent ? h. Extent of area involved. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 35 c. Q^dematous condition of the parts involved. d. Turbidity or clearness and colour of effused fluid in the ventricles. In noting the degree of sofleniiuj learn to appreciate how very short a period is requisite, after arrest of blood-supply, for the production of extensive nutritive changes. With what object do w^e endeavour accurately to map out the extmt of the destroying lesion ? Oui' object is to detect that portion of the vascular apparatus involved if the soften- ing be due, as it most frequently is, to plugging of a large branch. This, the more frequent source of extensive white softening, requires, therefore, for its full comprehension, an acquaintance with the vascular areas of the hrain. On noting the appearance of the serous ep)ision in the ventricles, so often accompanying white softening, the student will be guided towards concluding as to the presence or not of inflammatory action in the meninges or in the substance of the brain itself. Thus, if the fluid be more or less turbid and discolom^ed (as tlie result of a plastic exudate and macerated cerebral substance), we may reasonably suspect an inflam- matory condition, and expect to find, upon microscopic examination, exudation corpuscles, compound cells of Gluge, and other products of inflammation. Such are the conditions found in acute hj'drocephalus, distinguishing it from a purely non-inflammatory form of hydrocephalus, which occurs where the fluid, though perhaps slightly tm'bicl from broken-down cerebral tissue and shreds from the macerated lining mem- brane of the ventricles, presents no inflammatory material amongst the debris. 4. Limited Foci of Softening. — Acquaintance with the peculiar arrangement of the cerebral blood-vessels soon leads the student to infer that very minute tracts of softening- may result as the effect of thrombosis or embolism, the area involved being dependent upon the size of the clot and the site of its arrest or formation. It is necessary that the mechanism of white softening of cerebral tissue, as a result n 2 36 COARSE EXAMINATION OF THE BRAIN. of thrombosis or embolism, be thoroughly imderstood. The process may be best elucidated by the diagram below. a a Va Fig. 1. — Diagram illustrative of the Effects of Embolic Plugging (after Rindfleisch) . an. Portion deprived of its blood-supply Ijy the embolus. A, Artery. V. Vein filled with blood-clot. The airows indicate the collateral channels -which lead to a hyperfemic zone around the occluded vessels. Beyond the obstructed artery is the wedge-shaped area of its distribution, now anfemic and consequently deprived of its functional power. Below the embolus are seen swollen l)ranches, which tend to establish a collateral circulation. If this fails, we get as a result engorgement of the latter vessels, and a congestive vascular zone surroimding the wedge-shaped area. The tissue here becomes swollen and oedematous, and minute haemorrhages are apt to occur, whilst the whole central and peripheral texture becomes broken up by the effusion, and a true necrosis occurs of the tissue forming the area of distribution of the nutrient branch which has been plugged. All inflammatory foci have, as a result, the production of a similar congestion and aidema of the surrounding texture, accompanied by white softening ; and as new growths or tumovu-s are frequently the site of such inflammatory states, we may find them imbedded in a cavity containing broken- do\\Ti tissue. In addition, therefore, to the appearances which we have to look for in white softening of the brain, let us also note — Any obstruction to the vascular supply by thrombi, emboli. PHYSICAL PROPERTIES OF GREY AND AVHITE MATTER. 37 or adventitious products pressing upon tlie vessels from without.^ The establishment of a collateral circulation. The presence of inflammatory foci, to which the white softening is secondary. 5. Yellow Softening. — In the course of pathological studies we frequently meet with appearances which, whilst significant of cerebral softening, differ much from that just described. We find frequently in the white substances of the hemispheres, less frequently in the cerebellum, and rarely on the convolutionary siu'face of the cerebrum, a focus of softened tissue, varying in size, but scarcely ever larger than a hen's egg, and characterized by its bright straw-yellow coloixr and soft gelatinous consistence. Pressure causes a yellowish fluid to exude, and when cut across it is found to be somewhat sharply defined from the pale swollen and ojdematous tissue around. We recognize in these softened areas the lesion termed " yellow softening of the brain," Fmiher examination reveals the fact that these spots may be primary, or, on the other hand, secondarily induced around adventitious products, such as tubercle, cancer, cysts, haemor- rhages, or around a patch of inflamed tissue. If secondary to adventitious growths, there is, as Rokitansky points out, an intermediate zone of red softening betwixt the growth and the yellow softened exterior. It is important that these patches should not mislead the student. He must from the outset regard them as identical in natm-e ^vith the first form of softening described, the difference in colour being due, according to some, to altered blood-pigment, but according to Rokitansky, to a peculiar chemico-pathological process. The following facts are to be noted : — a. The fluid is usually intensely acid. h. There is little or no vascularity smTOunding the patch. c. Every degree of tint may be foimd, from white ' Plastic exudates, tubercle, .sypliilitic gummata. 38 COARSE EXAMINATION OF THE BR AIM. softening up to tlie bright yellow of typical yellow softening. d. Colour differs from the rusty or ochre-yellow tint seen in old apoplectic cavities, etc. c. Microscopic examination fails to reveal inflammatory products. 6. Red or Inflammatory Softening. — Profound altera- tions in consistence may thus attend inflammation of the nervous structures, and we find little difficulty in recognizing foci of inflammatory softening. "We occasionally meet with portions of acutely inflamed tissue in the medidlary strands of the cerebrum, varying in size from a hazel-niit to that of an orange, or still larger ; yet by far the more frequent site of such inflammatory foci will bo the grey cortex of the cere- brum and the basal ganglia. Examine a brain which presents a focus of inflammatory softening in the medulla of one of its hemispheres. Note the following facts : — The softenitig of texture is accompanied by modifications of colour and general moisture. Thus the increase in vascularity gives the affected part a streaky red aspect, often profusely besprinkled by puncta vasculosa ; the oedema- tous infiltration of texture is recognized, in its swollen and ^noist aspect. Where the engorgement has reached a high degree, note the numerous minute extravasations of blood, the streaked or punctated capillary haemorrhages. Now all the above characters may be developed in the course of extreme congestion. What impresses upon the affected part the stamp of inflammatory action is the presence of exudates, which modify the above-described appearances in two directions : — a. The dark red becomes of a paler and more uniform hue, whilst exudations of lymph still further modify the aspect. b. Alterations in consistence occur; rapid softening or solutions of textural continuity varying with the plasticity of the exudates. niYSRAL PROPERTIES OF GREY AND WHITE MATTER. 39 Observe, therefore, that the essential features of red inflam- matory softening are profound alterations of consistence, associated with the pouring out of inflammatory exudations. In advanced stages of red inflammatory softening, the student will, therefore, find the tissues broken down into a red- dish pulp, or having a brownish or rusty aspect, washing away freely when held beneath a stream of water. He will also note the results of swelling from congestion and oedema, viz., the flattening of the convolutions of the hemispheres from pressm^e against the internal table of the skull, and a well- marked prominence of the surface of a section of the inflamed and oedematous textures. Examine a patch of inflammatory softening in the coi-tex, and note : — Inflammatory foci situated in the cortex will implicate by contiguity the superimjjosed membranes. Observe in these cases that the grey matter is more deeply coloured, and is still more swollen, moist, and softened than when the white matter is involved. The far greater vascularity and the naturally looser texture of the grey matter account for this difference. Next direct attention to the state of the mem- branes. The pia mater cannot be removed without peeling off with it a layer of the softened cortex, whilst the meshes of the membrane are found inflltrated with inflammatory pro- ducts, and are both thickened and oedematous. As regards these apparent adhesions of pia mater, observe that the brain substance may tear away with the removal of the pia mater from two causes : — 1st. Mere unnatural softening and loss of textural cohesion of the grey matter, without any true adhesion to the mem- branes, as in early inflammatory and congestive stages, etc. 2nd. Actual adhesion, inflammatory in origin, may be the cause of this tearing of the cortex. How are we to distinguish the laeerable cortex in the former case from the genuine inflammatory adhesions of the membranes ? Note, in the former case, the surface left by the in-egular sln-eds torn off is soft, pappy, and uniformly smooth 40. COARSE EXAMINATION OF THE BRAIN. or liomogeneous ; in the latter case, tlie surface is studded with numerous perforations — the apertures of perivascular channels from which the blood-vessels have been withdi'awn. These channels will be seen much dilated from the prior engorgement of the blood-vessels, and the surface generally has a peculiar worm-eaten appearance. FALLACY TO BE AVOIDED.— We imxst not regard all cases of encephalitis as necessarily attended by injection and discoloration of tissue. The larger number of cases, in fact, show little or no discoloration ; and even where softening has advanced to an extreme degree, the naked eye fails to appreciate in the uniformly dull white pulj^y material its inflammatory origin. What criterion have we here for determining the nature of the lesion ? Resource must be had to the microscojie and specific gravity bulbs. The niicroscope shows us nuclei, nucleoli, pigment, and compound granule-cells amongst broken-down cerebral tissue infiltrated with leucocytes and effused lymph along the course of the blood-vessels. The specific gravity test (p. 63) will indicate an in- variable increase in specific weight where infiammatorij exudation has occurred, no matter whether the altered con- sistence be great or scarcely appreciable. On the other hand, non-inflammatory white softening shows an invariable reduction in specific gravity. By the freezing methods it will be possible to obtain fair sections through inflammatory patches of greatly reduced consistence, and much valuable information will be thus obtained ; but in all cases of extreme softening all that can bo hoped for is obtained by raising a little of the creamy pulp upon the scalpel, and transferring it to a slide and using a thin glass cover. Sections through the membranes and cortex, in cases where these are involved, will jirove highly instructive, and should never be neglected. They should be studied in the fresh state, and the student become PHYSICAL PROPERTIES OF GREY A^^D WHITE MATTER. 41 thorouglily familiarized with the morbid appearances ere he attempts to mount stained sections of such lesions for perma- nent preservation. Coarse blood-vessels passing through the inflamed patch shoidd be dra-\vn out and examined microscopi- cally, noting abnormal conditions of their coats and sheath. 7. CEdematous Conditions of the Brain. — It will be seen from the foregoing remarks that this morbid state of the cerebral tissue accompanies all cases of softening of the brain, whether inflammatory or non-inflammatory in origin ; yet it is thought ad\dsable here to consider it independently as a condition, often the only morbid one recognized by the naked eye, in the brain of the chronic insane. As it is chiefly compensatory in its origin, it will be considered together with that compensatory effusion into the ventricles and beneath the membranes of the brain which so frequently accompanies it. If the cerebral tissue becomes much infiltrated with serum, it is liable to break down the textiu-e of the brain. As before stated, this may proceed to a state of white soften- ing, in which the brain-tissue may become quite diffluent, such as we observe in the neighbom'hood of the lateral ven- tricles in acute hydrocephalus and around inflammatory foci. The more frequent condition met with in the brain of the insane is that of a general moist condition of the white matter, which is soft, almost pasty, clings to the blade, and is apt to tear away in shreds of a dirty white hue. Such is the appearance in cases of senile wasting of the brain. The white medullary strands immediately bordering upon the lateral ventricles will usually be found most implicated, being here in closer contact Avith the serum contained in these cavities. The lesser degrees of oedema are recognized by a pecuHar and notable brilliancy of the white substance when cut across, and is one of the most frequent appearances in the brain of the insane. The student must learn to recognize the general moisture, swollen condition, alterations in consistence, and alterations in appearance from a brilliant to a dull, dirty white Jnie, associated with varying degrees of oedema. 43 COARSE EXAMINATION OF THE BRAIN. If the freezing microtome be liberally used, he cannot fail to appreciate to the fullest extent the varying degrees of oedema of the cerebral tissue ; and this not only because it proves the most troublesome obstacle to a free manipulation of delicate sections, but from the tendency of cedematous brain to freeze into a hard icy solid, differing much from the consistence of healthy brain when frozen. It is impossible to cut through such frozen brains except by a modified process to be alluded to further on. In the hardening processes, also, these brains undergo, by dehydi"ation, enormous shrinking. The serous effusions beneath the arachnoid and into the ventricles, which have been alluded to as often associated with cedematous conditions of the brain, may occur as the result of — 1. Senile atrophy of the brain (compensatory). 2. Pressure by morbid products on the vessels, as in — Tubercular meningitis. Syphilitic disease of blood-vessels. Tumours. Growths, or abscesses of mid-lobe of cerebellum press- ing on venae Graleni. 3. As a gradual accumidation from anaemia and other existing morbid conditions, e.g.y chronic phthisis. Where does the effusion of serum attending oedema of the brain occur? 1. Into sac of the arachnoid, i.e., betwixt the cerebral layer of the arachnoid and the polished inner surface of the dura mater. On removal of the brain, we note this fact by examining the amount accumulated in the occipital fossae above and below the tentorium. 2. Beneath the cerebral arachnoid. Observe how the latter is floated up by the subjacent fluid where this mem- brane bridges across the sulci. 8. In the meshes of the pia mater. Note its swollen gelatinous appearance from infiltration with serum. 4. Into the ventricles, more or less distending the lateral PHYSICAL PKOPERTIES OF GKEY AND WHITE MATTER. 43 ventricles. Stretcliing tense the thin arachnoid which extends between the cerebellum and medulla over fourth ventricle. Before concluding the subject of oedematous conditions of brain and compensatory effusions of serum, we would recom- mend the student to acquire infoi'mation upon the following facts in all such cases : — 1. Condition of ependyma (lining membrane of ventricles). a. As to healthy aspect, h. Grranular appearance and feel. c. Macerated aspect. cL Fibro- cartilaginous plates. 2. Turbidity and coloration of serous fluid. 3. S^^ecific gravity of serous fluid. 4. Reaction to litmus paper. 5. Specific gravity of the brain. Augmented Consistence. — All cases of indm\ation of the brain should induce us to examine the morbid change in the texture as regards its degree, its diatrihution, and nature. The cases most likely to present themselves to our notice may be embraced under the following categories : — 1st, Greneral augmented firmness of the whole brain from increase of its connective or neuroglia element. 2nd. Limited but extremely indurated patches or nodules due to morbid growths, especially the carcinomata. 3rd. Limited indurations of grey or white matter due to transformation of inflammatory products. 4th. Sclerosis disseminated or distributed down the motor strands. The student will observe that the increase in consistence may vary from a scarcely appreciable degree, and due merely to a lessened quantity of water (Rokitansky) up to a condition of leathery callous consistence. A few words upon the varieties of sclerosis met with in cerebro-spinal centres independent of that general increased 44 COARSE EXAMINATION OF THE BRAIN. firmness from increase of neuroglia observed in the brain of many epileptics. 1. Superficial Scleroses. — We should also look for instances of partial sclerosis of the grey cortex occasionally to be seen in epileptics and imbeciles, and characterized by a peculiar shallow puckering of the surface of the gyri, which are somewhat indm\ated, and have a cauliflower appearance. 2. Hypertrophy of Neuroglia. — Again we may meet with instances of hypertrophy of the brain, as it is termed, which has been found due to extreme increase of the neuroglia around the medullary strands of the hemispheres. Such a case would present us with increase in consistence, elasticity, and volume. In all cases of general increased consistence it is imperative that the greatest attention should be paid to examination of the brain under the following heads : — a. Volumetric measurement. h. Absolute weight of brain and its divisions. €. Specific gravity of grey and white matter. 3. Cicatricial Formations. — The indui'ations resulting from inflammatory action will frequently attract attention. Such patches of callous tissue may surround foci of softening of the cortex due to plugging, or the site of old hsemor- rhages. Cyst-like cavities, with hard fibroid walls, may thus be formed deep in the substance of the hemispheres. Sections through such structures should be made for micro- scopic examination, as they illustrate well the various stages of transformation of inflammatory products into callous cicatricial tissue. 4. Disseminated Sclerosis. — If, in slicing a brain, greyish nodules are found scattered irregularly through the white substance resembling the cineritious substance in colour. THYSICAL PROPERTIES OF GREY AXl) AVHITE MATTER. 45 but becoming of a rosy hue on exposure, and exuding a colourless fluid, the student has probably to deal with a case of disseminated sclerosis. Note in such a case the increased consistence of the sclerosed patches, their yascu- larity, irregular distribution through the medullary substance, and the comparative immunity from this lesion enjoyed by the cortex. Sections should be preserved for microscopic examination. The extent of implication of the ganglia, pons, medulla, and spinal cord should also be examined. 5. Descending Sclerosis. — If again a greyish indiu'ation should be met with involving the white strands running down from the motor region of the brain to the internal capsule, or from the latter down into the crm-a, and on into the lateral columns of the cord, we are dealing with a secondary descending sclerosis (fasciculated sclerosis of Charcot) . § COLOUR. The alternating ligliter and darker shadings of the cortical layers vary much in the depth of their liue, rendering the distinctness or differentiation of the individual layers more or less apparent. The variations in hue from the normal standard may be distributed in mottled patches or laminated zones, or uniform ti/ spread thronrjhout the wJioJe cortical envelope. We should consider the conditions usually associated mth alterations in the coloiu- of the cortical layers, and first and most frequent amongst such conditions must be placed altera- tions in the hlood-supphj. The next most frequent condition met with is disintegration of nervous tissiie : next to these in their relative order of occurrence we find morbid deposits ; and lastly, new grouihs in the cortex. Let us first consider the morbid conditions associated -witli unusual pallor. 46 COARSE EXAMINATION OF THE BRAIN. 1. Partial Mottling and Laminated Pallor. — A very slight acquaintance with the morbid appearances found in the brain of the insane will suffice to attract attention to the frequent presence of irregular, oval, or circular patches of pallor, very limited in extent, and of a yellowish grey hue. These patches may extend throughout the whole depth of the grey matter or be limited to the superficial layers alone. Now this condition appears almost invaiiably attributable to antemie zones, in which special systems of arterioles are involved. It may, however, be due to granular disintegra- tion of nerve-cells and fatty accumulations in the peri- vascular sheaths. A similar patchy pallor will also be frequently met with in the central ganglia, but here it will usually be found asso- ciated with fatty degeneration of the nuclei in the walls of the blood-vessels. A portion of a convolution exhibiting this appearance should be placed on the freezing microtome, with the blotchy aspect uppermost. On freezing it will be observed that the whole depth of cortex assumes a uniform pallor throughout, and sections cut o& and floated in water /ail to exhibit t/ie pale patches if the latter be due to ana3mic conditions simply ; on the other hand, if due to structural disintegration, the appearance vanishes during the frozen state, only to return rapidly when the section is cut. The process of hardening by chrome salts dissipates all patches of pallor due to anaemic zones, for by both processes the blood-vessels are more or less emptied of their contents, and a uniform tint residts. Apart from the presence of fatty or granular debris, the general pallor of the cortex may be due to great paucity of nerve-cells, whilst the blood-supply being diminished the resulting pallor will be associated with a poor differentiation of layers. This apparent fusion of laj'ers and loss of the sharp boundary lines seen in healthy brain is therefore a fact of some significance ; it almost invariably points to general malnutrition and disintegration of nerve-cells. Pallor, how- ever, is not necessarily associated with disintegration of PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 47 nerve-cells, for tlie latter condition is frequently attended by vascular injection. 2. General Diffused Pallor. — I cannot do tetter here than describe the appearances fonnd in the case of a patient exhausted by phthisis, in which the typical palJor and mal- nutrition of the nervous centres is always so prominent a feature. Such cases are unfortunately so frequent in oiu' asylums that the student will have little difficrdty in pro- curing such a brain for study. Upon removal of the extremely thin, blanched skull cap, and reflecting the dm-a mater, the subjacent membranes were seen separated "widely from the surface of the brain, buoyed up by fluid which in part was clear and translucent, in part slightly turbid from films and flakes of lymph. The small arterial branches were not visible, the larger primary branches being alone apparent at the vertex. The venous sj^stem was represented by engorged trunks, their minutest radicles being well seen. The arachnoid where it crossed the sulci was more or less cloudy, the milky opalescence being due to interstitial change and lymph deposits. In the postero-parietal regions, where the membranes were floated by the distending fluid off from the siu-face of the gyri, the smaller veins could be traced meandering through the fluid, and dipping down to enter the cortex. Tracing the course taken by these vessels, the smallest radicles were seen emerging from the cortex, uniting here and there with larger twigs, which ramify through the serous fluid and cross obliquely or directly over the summit of the convolution, to terminate in the primary veins which are formed by their convergence. These latter veins run up the sulci on either side of the convolution, superficially exposed and directed towards the median line or longitudinal fissm'e, where they terminate in the longitudinal sinus. To render their distribution more apparent, we have only to compress the orifice of one of the larger superficial veins near tlie median line, whilst Avith the handle of the scalpel placed on a distal part of the same vein, we include numerous converging 48 COARSE EXAMINATION OF THE BRAIN. radicles betwixt the occluded points. Upon gradually draw- ing the handle of the scalpel along the course of the vein upwards, the blood is projected into these radicles, and innu- merable branchlets before invisible strike across the field over the convolution, or meander in tortuous arborescent forms through the subjacent fluid. The student will learn from the above examination the following relevant and useful facts : — 1st. The larger arteries being at the base, the smaller branches are alone seen near the vertex, and these usually deeply seated in the sulci. 2nd. All the larger blood-vessels usually exposed at the vertex are veins. 3rd. The direction taken by the minute venous radicles will be accurately learnt. 4th. A high degree of vascularitj^ simulating passive con- gestion may be induced artificiaUy with ease by slight force. It is necessary to observe here that great caution should be taken by the student against hastily arriving at any conclusion as to the presence of congestion of the brain from a super- ficial view of the veins at the vertex — upon this point the tyro constantly errs. " We must make it a rule to consider hypercemia of the cerebral membranes as proved only in those cases where the finest vessels are also injected, and where the overloading of the cerebral vessels is not at all in proportion to the amount of blood in other organs." ^ So says Niemeyer, reiterating a caution constantly given by pathologists, and as frequently neglected. Proceeding with our study of the anaemic brain, the membranes were next stripped and two facts noted ; they were slightlj^ thicker and more tough than in health, and ^Qj Avere removed with extreme ease. The student must be familiar with the difiicult}^ experienced in stripping the membranes from healthy brain, being recom- mended often to remove them under water. This difficulty is not alone due to the tenuity of the pia mater and arach- 1 Niemeyer' s " Practical Medicine," translated by Drs. Humphrey and Hackley, vol. ii. p. loo. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 49 noid, but also to the fact that the former membrane is attached to the siu-face by the prolongations of connective cells recog- nized as Deiter's corpuscles. These are by no means nume- rous in health, yet sufficiently so as to keep the pia mater in firm contact with the cortex. These cells are chiefly found in the neighbourhood of the vessels, where they enter the cortex from the pia mater, and both together they form an impediment to easy stripping. In cases of serous subarach- noid effusion, such as the one under consideration, the mem- branes have been floated up from the receding surface of the atrophic cortex, and the connections with Deiter's corpuscles have therefore been forced asunder. After noting fully the consistence of the brain accordmg to the plan ah-eady given, a section was made exposing the centrum semi-ovale, and the following facts presented themselves : — 1st. The blanched aspect of the cortex and the absence of any reddish striation of the upper layers, such as is seen when the cortical vessels are fidl of blood. The hue of the cortex was asht/ grey throughout, except in its most vascular zone, where perhaps the slightest warmth of tint was recognizable, but beyond this, nowhere did any blush suggest the presence of its extremely elaborate vascular apparatus. 2nd. The layers were individually very poorly differen- tiated. 3rd. The medulla was brilliant white, glistening, slightly reduced in consistence, and showed few or no puncta vas- culosa. "We must bear in mind that the vessels of the meninges may be tortuous and tm-gid with blood whilst the minute vascular supply of the cortex is absolutely diminished, and the layers appear blanched and anoemic. To a certain extent this was the case in the brain we have under consideration. How this occurs (passive or active hyperremia of the mem- branes associated with anaemia of the cortex) will be explained in our next section when speaking of hyperoemia of the brain. For the present let us mark well the fact that the vascular condition of the membranes is no index, as a rule, to the state of the cerebral substance. 50 COARSE EXAMINATION OF THE BRAIN. The brilliant white glistening aspect of the medulla was due, as will be shown fmiher on, to a slight degree of oedema of the brain-substance. Let us now place a small portion of a parietal convolution of thin and anaemic brain upon our freezing microtome, and cut a fine section through the cortex — float it on the glass slide and drain off superfluous fluid. Take a hand lens and examine first by reflected light. The cortex is seen as apparently to consist of — 1st. An outer light translucent zone extending half way down. 2nd. A. deep opaque white layer extending to the medulla, which is still more opaque and white in aspect. Eaise the slide and examine by transmitted light. We now see — 1st. The narrow translucent grey of the first or outer layer of the cortex. 2nd. A broad less translucent grey zone of the second and third layers. 3rd. A broad stripe of darker grey extending to the medulla, but separated at one-third its depth by a narrow bluish belt. We see thus by the naked eye the constitution of the cortex in this region of the brain, except that the narrow second layer cannot be defined from the third layer by unaided vision. Let us tiirn to the cortex prior to section cutting and examine by means of a hand lens imder re- flected light, and the appearances are as follows: — 1st. A grey belt corresponding to the first layer. 2nd. A broad white belt divided midway by a narrow grey line. 3rd. A grey belt constituting the deepest layer. We have, I think, gone sufficiently into the appearances afforded by the ansemie brain for our present pui-pose. The PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 51 examination of the various layers above recommended will prepare us not only for recognizing the relative positions of layers which have later on to be minutely studied, but will teach us to estimate roughly — a. The differentiation of the layers by naked vision. h. The relative depth of individual layers. c. The atrophy or normal depth of the cortex. d. The presence of morbid products. Of the latter I need here only mention those cases of so- called miliary sclerosis in which the nodules can be distinctly seen in sections on examination by reflected ligJtt, dotting the surface over mth minute opalescent spots. Let us now recapitulate shortly the observations to be made when examining by naked vision a cortex of unusual pallor : — 1st, The extent of pallor throughout the brain. 2nd. Its limitation in depth through the cortex. 3rd. Its disposition in patchy areas or otherwise. 4th. Its association with obscure laminar boundaries. 5th, Its association mth pigmentary tints. 6th. Its association with altered consistence and oedema. 7th. Its reappearance in sections from frozen brain. 8th. Examination of sections by transmitted and reflected light. Redness. — The depth of tint acquired by the grey layers of the cortex depends not alone on the presence of pigmented nerve-cells, but also on the far greater vascularity of the grey as compared with the white matter, whilst the layers most richly supplied with nerve-elements possess also the more abundant capillary supply. The more vascular the layer is, the deeper and warmer will be its tint. Now the capillaries of the cortex are of remarkably fine calibre, and hence, when the ultimate arterioles are injected, the appearance resulting is that of a uniform rosij hlunh more or less dark, the surface smooth and sicollen. This uniform coloration, if at all extreme, is often attended by slight extravasations of blood, and the E 2 52 COARSE EXAMINATION OF THE BRAIN. tissue around presents a different staining from blood-pigment. Such are the conditions found in genuine congestion of the. cerebral substance, and the analogous condition is readily recognizable in the soft membranes. The student must make himself thoroughly acquainted with the evidences of a genuine active or passive congestion of the brain, and learn to . distinguish it from actual inflammation, where, as ak-eady pointed out, the consistence as well as colour are profoundly implicated, and the specific gravity also affected. 1. Congested Zones. — One of the most frequent appear- ances in the cortex of the acute forms of insanity, is a bright arterial zone, which bounds the confines of the white and grey matter of the convolutions, following out accurately the direction of the innermost cortical layer. This congested belt corresponds to the horizontally disposed nexus of blood-vessels into which the larger straight cortical arteries empty themselves after passing through the various cortical layers. Any undue engorgement of the vessels of the pia mater will necessarily affect these larger blood-vessels, and, from their general arrangement, a mechanical element is brought to bear, such that, as I shall endeavour to show fiu-ther, is significant of a safety-valve action for the cortex in cases of vascular engorgement, relieving the cortex some- what by their distension from congestive conditions. It is on this account, I believe, that this linear vascularity is so often apparent without a corresponding blush in the cortical layers, indicative of distension of the minute capillaries. 2. Limited Patchy Congestion of Cortex. — When, however, the cortex is itself congested, the student will frequently observe irregular bright red patches, suggestive, like the anaemic patches already referred to, of the implication of minute vascular areas, whilst leading down to them are seen the distended straight cortical vessels, giving the upper layers a reddish streaked aspect. The last act of arterial contraction, in ^hich the smaller arterioles have failed to PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 53 empty themselves into the venous system, may in part explain this appearance, and caution is necessary, lest we hastily assume that this state is the result of morbid activity. The student should, therefore, examine closely the injected part by the microscope, and look for evidence of minute extrava- sations, hsematine crystals, and staining as well as broken- down texture, or other results of inflammatory action and of congestion. This blotchy red aspect of the cortex reappears very frequently in the medulla in similar cases, and is indica- tive of engorgement of the minute capillaries of these regions. 3. Puncta Vasculosa. — It is customary, in judging of the degree of engorgement of the vessels of the white matter, to be guided by the paucity or abundance of the puncta vascu- losa, caused by section of the engorged channels — in other words, the number of drops of blood oozing from the divided vessels are supposed to form some criterion of the engorged condition of the vascular system here. It has been shown by Niemeyer that this is no safe criterion, as 1st. The number of puncta vasculosa vary greatly with the fluidity of the blood, which is an important element in their causation. 2nd. They are often almost entirely absent when we have had indisputable evidence of intense vascular engorgement during life. We must, therefore, be on our guard against attributing too much importance to abundant bloody points on section of the medulla, whilst we should never fail to note whether this condition is or is not associated with distension of the minute capillaries as indicated by fine diffuse patchy redness. I need not here dwell upon the changes of coloiu' due to inflammatory action, as these have been already disposed of when illustrating anomalies of consistence ; but I must here repeat the important caution that the student be not misled by expecting to find engorgement and redness in all cases of encephalitis. The larger number of such cases present no undue red coloration. 54 COARSE EXAMINATION OF THE BRAIN. Results of Intra-cranial Pressure, — Due allowance must be made for conditions of increased intra-cranial {hut extra-vascular) pressure. Wlien the cranial cavity is en- croached upon by a tumour, abscess, hsemorrhage, or serous accumulation, compensation is made by the outflow of the subarachnoid fluid into the spinal meninges. The limit of this compensatory arrangement is soon reached, and then the only available space is that gained at the expense of the general vascular calibre. Encroachments upon the cranial cavity therefore eventually empty the blood-vessels, causing partial or more or less general anaemia prior to compression of the brain-substance itself. It is therefore far from improbable that, as Niemeyer teaches, engorgement of the blood-vessels may reach such a degree, that after the limit of subarachnoid compensation has been reached, effusion of serum occui-s into the perivascidar spaces and brain-tissue, and suiflces to com- press the minuter blood-vessels and capillaries. Hence we may find in such cases an association of marked cerebral anaemia with tortuous and engorged blood-vessels in the meninges. Results of Intra-thoracic Pressure. — Venous engorge- ment of the brain is a fi'equent result of obstructed circula- tion through the medium of pleuritic effusions, intra-thoracic growths, fibroid ind oration, and other changes obstructing or obliterating the vascular system of the lungs. Occasionally, although rarely, there is found an extraordinary engorgement and varicosity of the veins of the pia mater — the vessels winding in all directions, and, as Eokitansky states,i even in spirally -twisted coils and intestine-like ciiTiunvolutions. In these cases the brain-substance will be found dark and engorged, full of puncta vasculosa and even miliary apo- plexies. In one very typical case occurring at West Riding Asyliun the brain-surface was actually concealed over exten- sive tracts by a vast development of varices and contorted vessels, and when cut into, the grey and white substance was ' " Patliological Anatomy," Sydenham Soc. vol. iv. pp. 372-3. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 55 not only deeply engorged, but presented very numerous miliary haemorrhages, forming patches varying from a pea to a florin in extent, and in all degrees from the purely punctif orm to the diffuse uniform extravasation. A similar case was ex- hibited some years back by Dr. Coupland at the Pathological Society of London.^ In this case the mechanical hyperaemia was due to acute bronchitis — in the Asylum case the imme- diate cause was the supervention of capillary bronchitis upon fibroid limgs in a patient who gave a history of intemperance. Its association with diink has been recognized by Rokitansky. The occm-rence then of such cases should direct the student's attention to the effects of intra-thoracic pressure upon the venous circulation of the brain. § VOLUME. Volumetric Methods for the Brain. — The cubic measm^ement or volume of the encephalon can be very readily ascertained, and considering the important information it affords, it is a process too frequently neglected in our post- mortem rooms. The volume of the brain is estimated by its displacement of fluid. 1. Dr. Hack Tuke has detailed, in the January number of the British and Foreign Medical Review for 1855, the result of examination by this method of sixty-three brains, together with the capacity of the crania.. The vessel used by this observer was one of convenient size and shape, with a capacious spout placed at an acute angle with the sides. Water is poured into this vessel up to the level of the spout. Fluid contained mthin the ventricles and subarachnoid space is allowed first to escape by several long incisions, and then the brain, including the medidla oblongata, is immersed, the displaced water, as it escapes from the spout, being caught and measured, affording an exact criterion of the actual bulk of the brain. The student may, however, prefer the use of a ' Reported in the Lancet for January 11, 1879. 56 COARSE EXAMINATION OF THE BRAIN. graduated vessel upon which lie can at once read off the dis- placement of fluid, but the exact graduation of large vessels, such as would be required, is open to several fallacies ; and these possible sources of error are, of course, wholly avoided by Dr. Hack Tuke's method. If such a vessel as that used by Dr. Tuke be not at hand, a ready method is the one I have used, as follows : — 2. Half fill with water an inverted bell-glass of sufficient dimensions, and mark the level of the fluid. Now immerse the brain in the fluid, and note the level of displacement, after which the brain is removed ; and, if the original level is not exactly maintained owing to imbibition by the brain, pour in sufficient fluid to compensate for the loss. Water is now poured in from a graduated measure up to the displace- ment level, the amount required for this pui^pose giving us the volume of the brain. The volume should be estimated in cubic centimeters and cubic inches. I employ for section-cutting a vessel which answers well for the volumetric estimate of the brain. It consists simply of a large glass vessel, such as is used for the preservation of brain in museums, but fitted with a stopcock arrangement in the side near the bottom of the vessel. It is filled with sufficient water to cover the brain, the level being marked or indicated by a weighted float. The brain is next immersed, and whilst so immersed, the fluid of displacement is run off by the stopcock, and measm-ed in a graduated vessel. Again, in lieu of a graduated vessel, the student may emj^loy a float, movable along a graduated weighted stem (gradu- ated, of coiu-se, for the vessel used). Such a float should terminate below in a brass button, which rests against the bottom of the vessel, keeping the graduated stem in a vertical position, whilst the float freely moves with the rising or falling level of the fluid along the graduated stem. 3. When referring to the specific gravity of the brain an apparatus will be described whereby volume as well as weight of brain are readily measured.^ Such an apparatus ^ Stevenson's Displacement Apparatus, vide p. 65. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 57 has the recommendation of being cheap and efficient. Whatever arrangement be adopted we should not rest content with the estimate of the volume of the encephalon alone. Each hemisphere should be separately measured, as also . the cerebellmn, pons, and medulla. It will be found convenient to use smaller and more delicately-graduated vessels for the latter. Cranial Capacity. — This should be estimated Avith a ■vdew to a comparison between the actual volume and weight of the brain and the dimensions of the cranial cavity, as well as for comparison with the capacity of average-sized skulls. The relationship between cranial capacity and brain- weight has been sho\\Ti by Dr. Barnard Davis, who has adopted the general rule that a deduction of about fifteen per cent, from the capacity of the cranium gives the ^' capacity " of the brain, whereby its weight may be readily calculated.^ The large bulk of cranio-metric observations having been taken upon the cliied skull, we should, when dealing with the fresh subject, make allowances for slight divergence ; and, in order to approximate the conditions, the dm-a mater should be wholly removed from the skull- cap and the base. When, however, our intention is to estimate the difference in any single case between cranial capacity and brain-volimie, rather than for more general comparative purposes, it will be necessary to open the skull prior to opening the thorax, so as to avoid emptying the venous sinuses, whilst at the same time the diu-a mater must not be stripped away from the skull-cap nor the base be uncovered. 1. With the object of estimating the amomit of cerebral atrophy, a valuable series of observations were made by Dr. Hack Tuke, and the process he adopted is described as follows : — " The foramina at the base of the brain are ^ *' On the Weight of the Brain in the different Races of Man." Thilos. Trans., 1868, pp. 506 and 526. 58 COARSE EXAMINATION OF THE BRAIN, carefully plugged witli tenacious clay — that used by statu- aries for modelling answers best ; a small triangular piece of the frontal bone is removed with the saw ; the calvarimn is readjusted to the base, the dm^a mater being left attached. The space left by the attrition of the saw in removing the calvarium is filled with clay ; and a narrow bandage with clay spread upon it is made to surromid the cranium three or four tunes, covering this space. If this manipulation has been carefully done, the cavity of the cranium will now be found as tight as a bottle. Sixty fluid ounces of water having been measured, a sufficient quantity to fill the cranial cavity is now poured into it by means of a funnel, through the orifice in the frontal bone, taking care that the stream does not wash away the luting of the foramina. The fluid which remains, after having filled the cranial cavity, is measm^ed, and being deducted from the sixty ounces gives the amount emj)loyed. To this must be added half an ounce for the space occupied by the luting." Having thus obtained the cranial capacity, he deducts from it the brain volimie, and obtains thus the exact measui^ement of shrinking or atrophy. Millet seed and sand have been used for measur- ing the capacity of the cranial ca^dty, and the latter in the dried skull has answered admirably. It must, however, be borne in mind that a fallacy may be introduced by the employment for this purpose of materials liable to be influenced by temperatm'e. Fluids are, of course, more open to this objection, their expansion by heat being pro- portionately more rapid than solids, and hence it would appear that sand is preferable to water in these investiga- tions. 2. Mustard seed was employed by Professor Flowers in his extensive series of researches.^ 3. The method adopted by myself arose from my em- ployment of solid paraffin in obtaining casts of the brain- ' The capacity of the crania contained in the Himterian Museum of the Royal College of Surgeons was obtained by Professor Flowers in this manner. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 59 surface, and the interior of tlie skuU. It was soon apparent that the finest and most delicate impressions and most perfect casts coidd be obtained by the use of this substance, and that it did not share in the great disadvantage which accrues from the use of plaster of Paris, viz., that of great con- traction during solidification. It is in this respect also far superior to white wax, which, as is well known, contracts much whilst solidif jing. I proceed as follows : — Fill up the foramina at the base as pre\iously described. A tri- angular or wedge-shaped piece is now sa^vn out of the occipital bone after removal of the calvarimn, but retained in situ. The base is then filled up by melted paraffin, the skrdl-cap replaced and fastened by luting, just as in Dr. Tuke's process, having previously trephined a piece out of the frontal bone. Through the latter orifice more of the paraffin is poiu"ed in imtil the cranial cavity is filled. When cool and solid remove the calvarium, as well as the wedge- shaped piece of bone from the occiput, and then gentle pressure from behind tilts the solid mass out of the cranium, Avhen it will be found to form an exquisite mould of the interior. The moidd thus obtained is now to be measured by displacement, whence we obtain the cranial capacity. This method has afforded me great satisfaction, as it gives data of great value at the expense of very little trouble : it supplies us with a method of — 1st. Estimating cranial capacity. 2nd. Grives us an exact mould of the cranial cavity. 3rd. As a permanent record — numerous linear angular measurements and volume measiu-ements may be obtained. 4. From some invaluable measurements by the late lamented Broca,^ it was found that of 115 skulls of indivi- duals living in the tweKth century, the average capacity was 1425 "98 cubic centimeters ; whilst of 125 skulls of the nine- teenth century the average capacity was 1461'53 cubic centi- meters. The following table of percentage will be found of 1 Quoted by Vogt, " Lectures on Man." Anthrop. Soc. 60 COARSE EXAMINATION OF THE BRAIN. use by those interested in the subject of cranial capacity. It is given by Le Bon as illustrative of the relationship of race to cranial capacity : — Cranial Capacity in different Human Races. CRANIAL capacity. Modern Parisians. Parisians of 12th Cent. Ancient Egyptians. Negroes. Australians. Cubic Centimeters. 1,200 to 1,300 . 0-0 0-0 7-4 45-0 1,300 to 1,400 . 10-4 7-5 12-1 35-2 25-0 1,400 to 1,500 . 14-3 37-3 42-5 33-4 20-0 1,500 to 1,600 . 46-7 29-8 36-4 14-7 10-0 1,600 to 1,700 . 16-9 20-9 9-0 9-3 0-0 1,700 to 1,800 . 6-.5 4-0 0-0 0-0 0-0 1,800 to 1,900 . 5-2 0-0 0-0 0-0 0-0 § WEIGHT. Gravimetric Methods. — The student must make him- self familiar with the various circumstances which modify brain-weights. Some of these conditions have been sum- marised by Bastian.^ They appear to be chiefly as follows : — 1. Length and natm^e of illness. 2. Mode of death (vascidar engorgement favom'ing high weight). 3. Certain neuroses, as epilepsy. 4. All conditions inducing sclerosis. 5. Atrophy. 6. Congenital micro- or megalo-cephaly. The student must also take into consideration the relationship between weight of brain and the age and sex of the individual as well as the weight and height of body. ^ ''The Bruin as an Organ of Mind," chap. xx. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 61 Absolute Weight of Brain. — Before weighing tlie brain, all fluid from the subarachnoidal space and ventricles must be di-ained off, and allowance made for the membranes, which will scarcely exceed an oimce in weight. The plan adopted at the "West Riding Asylum, however, is to first strip the brain of its membranes, to liberate the fluids in the ventricles, and weigh the whole encephalon. The membranes can afterwards be weighed if thought necessary. In all cases when the pia mater is firmly adherent to the cortex, it is as well to weigh the brain prior to stripping, as large shi'eds of the cortex are often removed in these cases. Pre- caution must be taken, however, by incisions, to release any accumulation of fiuid in the subarachnoid spaces and meshes of the membrane, and, subsequent to weighing, allowance must be made for the pia mater and arachnoid. After the weight of the encephalon has been obtained, the cerebellum and pons must be removed by di\iding the crura cerebri close to the pons} A longitudinal incision is then carried through the median line of the corpus callosum from before back- wards, so as to separate the two hemispheres. The pedun- cular connections of the pons and medulla with the cere- bellum are then divided, and the former (pons) also separated from the medulla at its natiu-al line of division. This is the method adopted at West Riding Asjdum, but for several years it was the custom here to separate the frontal lobes from the remaining posterior part of the brain by an incision carried through the fissure of Rolando, The weights of these individual parts are then taken. It will be foimd ad\dsable to use the metric system in aU our estimates of capacity, volume, and weight, and all the standard brain-weights afforded by the elaborate tables of Tiedemann, Reid, Boyd, Wagner, and others shoidd be expressed in grammes rather than ounces. Dr. Sharpey, after an elaborate analysis of brain- weights given by Grlen- ' A modification of the plan is recommended in tlie section on the dis- section of the brain as preferable when the question of weight is of secondary import (p. C9). 62 COARSE EXAMINATION OF THE BRAIN. dinning, Sims, Tiedemann, and Reid, supplies us with the following valuable results : — ^ ozs. Maximum weight of adult Male Brain 65 Average » )) 5) 49^ Minimum ») )) )» 34 Maximum „ „ Female Brain 56 Average » » j> 44 Minimum )) 5> »> 31 The heaviest human brain on record has been described by Dr. Morris,^ and was carefully examined at University College Hospital : the weight was 67 oz. Compatible with ordinary intelligence, the lowest limit of the human brain, as regards weight, is, according to Gratiolet, 900 grammes, and, according to Broca, 907 for the female, and 1049 grammes for the male.^ Specific Gravity. — Researches upon the specific gravity of the encephalon are becoming more and more interesting with our knowledge of cerebral localization and intimate brain- structure. The late suggestive work of Danilewsky upon the relative amount of grey and white matter in the brain depends greatly upon the accuracy of the specific gravity for its cor- rectness. The more important methods adopted are those of Drs. Bucknill, Sankey, and Peacock. 1 "Elements of Anatomy," 7th Edition, vol. ii. p. 568. 2 Brit. 3Ied. Journ. Oct. 26, 1872, p. 465. 2 Quoted by Bastian, "The Brain as an Organ of Mind," 1880, p. 365. In connection with the weight of the brain in the insane, the student will find most valuable information in articles by Dr. Crochley Clapham, contained in the 3rd and 6th vols, of the "West Riding Asylum Medical Reports." His observations embrace 1,200 cases of insanity. Fiu-ther information upon this subject may be obtained by reference to the following : — Sims, Medico-Chirurt/. Trans, vol. xix. ; Glendinning, Medico- Chirurg. Trans, vol. xxi. ; Tiedemann, " Das Hirn des Negers," Heidelberg, 1837 ; Reid, London and Edin. Month. Journ. Med. Science, April, 1843 ; Thurman, Journ. Mental Science, 1866 ; Wagner, " Vor.studien," 1862, 2' Abh. pp. 93-95 ; Peacock, Month. Journ. Med. Science, 1847, and Journ. of Tathol. Soc. 1860; Boyd, Philos. Trans. 1860; Bastian, " The Brain as an Organ of Mind," 1880 ; Clapham, loc. cit. and Journ. of the Anthropolog. Inst. vol. vii. p. 90. PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 63 1. Buckniil's Method. — Dr. Biicknill was tlie first who originated a satisfactory and ready method for estimating the specific weight of brain. The foUomng is his detailed account of the process : — " The specific gravity of the cerebrum and cerebellum is ascertained by immersing a portion of each in a jar of water wherein a sufiicient quantity of sulphate of mag- nesia has been dissolved to raise the density of the fluid to the point required, adding water or a strong solution of the salt, until the cerebral mass hangs suspended in the fluid without any tendency to float or sink, and then, by testing with the hydro- meter, the specific gravity is thus f oimd with great delicacy and facility, a difference of half a degree in the density of the fluid being indicated by the rise or fall of the substance immersed. The soluble salt is chosen, for its possessing no astringent or condensing action upon animal tissues."^ 2. Sankey's Method. — This pro- cess is the one which has been used most extensively by Dr. Crichton Browne at West Riding Asylimi, and it is the method which I have myself invariably adopted. It appears to me in every respect highly satisfactory and simple. "We require a series of cylin- drical glass jars, such as the one figured, and a set of graduated hollow glass bulbs, which can be readily obtained.- These glass bulbs are accm-ately graduated, or r Fig. 2. Specific Geavxty Test. now rather marked with the specific gravity of the fluid in which they 1 Lancet, 1852, vol ii. p. 589. 2 Such a set of graduated bulbs may be obtained of Mr. Stevenson, Philosophical Instrument Maker, No. 9, Forrest Road, Edinburgh. 1031 1032 1033 1034 1032 1033 1034 1035 1033 1034 1035 1036 64 COARSE EXAMINATION OF THE BRAIN. would liang suspended when immersed, neither tending to float nor sink. The glass jars are partly filled with water, and then a concentrated solution of Epsom salts added to each, until its specific gravity is such that whilst one bulb floats, a bulb two degrees higher sinks. Thus a series of jars are filled as represented below : — Bulbs floating .... 1030 Specific gravity of fliiid = 1031 Bulbs sunk 1032 The middle line represents the specific gravity of the fluid, and therefore of the portion of brain which tends neither to float nor sink, but to remain suspended wherever placed. It will occur to the student that the jars may be so graduated, that whilst one bulb floats, another, one degree higher, sinks, and hence that half a degree specific gravity may be indicated as follows : — Bulb floats 1030 1031 Specific gravity of fluid and suspended body 1030'5 1031-5 Bulb sinks 1031 1032 This is a degree of nicety, however, to which the use of the beads shotdd not be pressed, and if required, should demand in preference the use of the 1000-gramme specific gravity bottle. A series of jars should be graduated from 1028 to 1050, so as to enable us to deal withwhite or grey matter of cerebrum, cerebellum, and central ganglia. Occasionally still more dilute solutions mil be requisite. A minute piece of white or grey matter is now raised by a scalpel and placed upon the perforated spoon or scoop, which is gently lowered into one of the jars of saline solutions, and the fragment of brain tm-ned off the scoop and closely observed. If it sinks, it is of course of higher specific gravity than the fluid, and must be passed on to stronger solutions until, reaching one of its o^ti density, the fragment remains stationary where placed. If, on the other hand, it floats, it must, of coiu-se, be moved to a solution of less specific weight, until the same conditions are obtained. Should the specific PHYSICAL PROPERTIES OF GREY AND WHITE MATTER. 65 gravity beads be cbosen by the student for tliis purpose, it would be well for him to attend to the following rules : — a. After obtaining the specific gravity of any one portion of brain, repeat the trial with fresh portions at least two or three times, so as to ensure perfect accuracy. b. Examine the brain as soon as possible after death, wholly rejecting such as show the least evidence of com- mencing decomposition. c. Keep the jars covered with glass squares in a cool room, so as to avoid dust and evaporation as far as possible. d. Before commencing any series of observations, note the position of the bulbs, any tendency of the lower bulbs to float from evaporation of the solution being rectified by the addition of water. 3. Stevenson's Displacement Apparatus. — A simple and most reliable apparatus has been devised hy Mr. Stevon- FiG. 3. — Stevenson's Displacement Api-aeatus. son for estimating at the same time both the bulk and specific gravit}' of large irregular bodies by the principle of displace- F 66 -OOARSE EXAMINATION OF THE BRAIN. ment. Tlie apparatus consists of a jar, A, fitted -witli a large drooping tubidatiu'G, B, with stopcock attached. A metal gauge, D, having a thin horizontal straight edge inside the jar, determines the exact water-level, and over it the surplus water flows. The other jar, E, is graduated on the sides into cubic inches, avoirdupois lbs. and ozs., and thousandth parts of a gallon. The packing case, Gr, serves as a stand for the jar. In taking the specific gravity of the brain, or any body a little heavier than water, the jar must be filled with a solution of salt or sulphate of magnesia up to the level of the gauge, the stopcock being closed. The brain is then immersed in the fluid, in which it ought to float, and the fluid immediately rises in the jar; let it come to rest; open the stopcock, and the quantity displaced Avill flow into the graduated jar and represent the u-eight-indication of the brain (since any floating body displaces exactly its own weight of the fluid) . The stopcock is now shut, and the brain depressed by the brass piece, F ; and when the water has again come to rest, open the stopcock and receive the f m-ther displacement in the jar E. The whole bulk of displaced fluid read off the graduated jar indicates, of course, the volume of the brain. To obtain the specific gravity, multiply the weight-indication by the specific gravity of the fluid and divide by the vokmie- indication. I need scarcely indicate to the student the simplicity and value of this method, whereby the weighty the volume, and the specific gravity of the brain may be simul- taneously obtained.^ The apparatus, as figiu-ed, is somewhat smaller than what would be required for brain. In estimating the specific gravity of the encephalon, the student will soon appreciate the fact that the specific weight varies not only in the cerebrum, central ganglia, and cere- bellum, but that variations occur over different regions of the cerebrimi, suggesting the importance of a comparative examination by this method of the various cerebral con- volutions. By cautious manipulation he will also be able to show that the specific gravity of the cortex varies with its ^ This apparatus is sold by Mi\ Stevenson, 9, Forrest Road, Edinburgh. PHYSICAL PROPERTIES OF GREY AND AVHITE MATTER. 67 deptli. Dr. Sankey otserves that the specific gravity dimin- ishes in the ratio of •001 for every twenty-four hoiu's after death. This must, however, be greatly modified by the temperatiu^e of the surrounding atmosphere, and other condi- tions favouring putrefactive changes. The folloAving embrace the more important residts obtained by different observers, and they will serve as a useful guide to the student in his prosecu- tion of similar observations ^ : — Average specific gravity of whole Enccphalon 1036 (Ikicknill) )» Cerebrum 1030-'48 (Aitkin). )» Cerebellum 1038-'49 (Aitkin). »> Grey matter 1034 (Sankey). j> White matter 1141 (Sankey) . )) Central ganglia 1040-'47 (Aitkin). Proportion of White and Grey Matter in the Brain. — Tlie specific gravity of the grey and white matter, together with that of the whole brain, has been applied to solve the very important problem of the relative percentage of grey and white matter in the human brain. Danilewsky has lately published his results and method of procediu'e, an account of which may be seen in the Ccntralblatt f. d. Med. Wissenchaftci), No. 14, 1880. ^ The formula given by him is as follows : — X = — Y- ^ where x is the quantity of grey or of white matter, p the specific, grcmty of the whole brain, a of the grey and h of the white substance, and P is the weight of the Avhole brain. He gives, as the results of one series of experi- ments, a percentage for the grey matter of 37'7 to 39, against a percentage of 60'3 up to 61 for the white substance. By taking the average depth of grey matter it is, of course, an ^ References to work done in the Specific Gravity of the Brain : — Bucknill, Lancet, vol. ii. 1852, and the Med.-Chir. Rev. 18-55; also " Psj^chologica 1 Medicine," Bucknill and Tuke, 3rd edit. pp. 520 and 587; Sankey, Brit, and For. Mcd.-Chir. Rev. 1853 ; Peacock, " Trans. Pathol. Soc. of London," 1861-2 ; Aitkin, " Science and Practice of Medicine," 1865, vol. i. p. 265. ^ Vide Abstract by Dr. Geoghegan, Journ. Mental Science, p. 437, Oct. 1880. T^ 9 68 COARSE EXAMINATION OF THE BRAIN. easy matter to obtain tlie surface measurement of the brain. Wagner's researches upon the superficial area of the brain are of interest here.^ The student, however, must be warned against regarding results so obtained as other than merely approximate^ as it is next to impossible to exclude the numerous fallacies to which the estimation of average specific gravity is liable. Thus the specific gravity of the grey matter is known to vary with its depth, with its local distribu- tion or area, with the amount of vascularity of the tissue, and time after death. Beyond this the very cases in which the pathologist would be interested in estimating the relative proportions of grey and white matter are those which are subject to such diffuse and local change in consistence that an average specific gravity for either white or grey could not be attained with any degree of exactness. For comparative investigation of healthy brain, the process adopted by Danilewsky promises to afford valuable results as long as the greatest care is observed to exclude fallacies. 1 Quoted in Quain's " Anatomy," vol. ii. CHAPTER V. REMOVAL AND DISSECTION OF THE BRAIN. § EXTERNAL ASPECT OF THE BRAIN. It may be usefiJ here to review the course to be piirsiied in removing and preparing the various parts of the brain for coarse examination, and the following method is recommended as in every way the more reliable and satisfactory one. In the fii'st place the head should be so supported as to command a good light and a full and satisfactory view of the brain i)i dtii. In the next place never neglect the rule of o]iening the skull and examining the brain ^j/vor to opening the thorax and dividing the great vessels. Cranial Membranes and External Aspect of Brain. — The skull-cap having been removed sec. art. we proceed as follows : — ' 1. Examine upper surface of dura mater in its relation- ships to the skull (pp. 3-5). 2. With a forceps raise a fold of dm-a mater anteriorly, run the scalpel through it, and carry the blade along either side on a level with the sawn edge of the cranium far back towards the occiput, stopping short of the middle line. 3. Reflect these lateral halves of the membrane towards the middle line, observing the condition of the large super- ficial veins running into the longitudinal sinus. 4. Replace the dura mater, and with a curved bistomy 70 COARSE EXAMINATION OF THE BRAIN. open up the longitudinal sinus in • its whole length back towards the torcular herophili, noting the condition of the parts (p. 5). 5. Divide the connection between dura mater and crista galli, and seizing the anterior end of the falx cerebri, forcibly draw the membrane backwards, dividing the junction of the superficial veins in this course, and thus expose the surface of the hemispheres. 6. With a good light thrown on the subject, and, if requisite, the aid of a hand lens, observe the appearances presented at the vertex, noting the condition of the vessels, membranes, and general conformation of the brain. It is absolutely necessary to pay attention to this point, as the appearances presented in situ are often greatly modified or wholly lost upon removing the brain at a later stage. 7. Grently raise the tips of tlie frontal lobes from the orbital plates, carefully removing the olfactory bidbs with the brain, and then using a little gentle traction, the optic nerves are exposed and divided close to their foramina. With the same blunt-pointed curved bistomy divide suc- cessively the infundibulum, carotid arteries, and third nerve. A good view is thus afforded of the tentorium, which should be divided along its attachment to the ridge of the temporal bone, dividing at the same time the fom-th nerve. The base of the brain is now exj^osed, and the fifth, sixth, and seventh nerves readily divided, after which the blade is passed do-wn into the vertebral canal on either side of the medulla, and, cutting forwards, it severs the vertebral arteries, the eighth and ninth pairs, and spinal accessory nerves. A sweep of the scalpel across the front of the cord liberates the brain, which can be now raised out of the cranial cavity with ease. 8. The next procedm^e is to place the brain base upwards in the skull-cap, the latter being conveniently steadied by any simple contrivance. This enables us with less sacrifice to the appearances at the vertex, to study the important region of the base. In doing so, follow out the instructions REMOVAL AND DISSECTION OF THE BRAIN. 71 already given (p. 15), taking the parts in the following order : — a. Arrangement and appearance of the great vessels at the base. h. Condition of the membranes and subjacent gyri. c. Condition of the various cranial nerves. (/. Open up the fissure of Sylvius on either side, tracing the large arterial branches upwards ; also examine nutrient supply to the basal ganglia at anterior and posterior perforated spots. e. Strip the base of its membranes, noting adhesions, etc. etc. 9. The cerebrum may now be turned out upon the dis- secting tray, with vertex uppermost, and the membranes carefully examined and stripped. Take note of the arrange- ment of the gyri, the presence of superficial lesions, general consistence, and coloiu'. 10. The clui'a mater and its sinuses at the base of the skull may be now examined (p. 8), completing thus the examination of the cranial membranes and the external aspect of the brain. § EXAMINATION OF INTERNAL STRUCTURE OF THE BRAIN. 1. Introduce a large section knife into the longitudinal fissure, and cut outwards across each hemisphere, about | inch above the corpus callosmn, exposing the centrum ovale minus. Repeat the same procedure on a level with the corpus callosum, exposing the greater centrum ovale, and exhibiting the continuation of the transverse strands of this great com- missm-al tract with the medulla of the hemisphere. The student will now proceed to note the relative and absolute amount of grey and white matter, and incj^uire into the con- sistence, colour, and other physical qualities of these parts in the manner abeady detailed (Chap. IV.). 72 coause examination of the brain. 2. By an incision carried from before backwards across the fibres of the corpus callosimi, a short distance on each side of the median line, the lateral ventricles are opened. To expose the structures more fully, divide the corpus callosum anteriorly, and whilst gently reflecting it cut backwards, with a scissors, through the vertical septum (septum lucidum) , which is attached to its under surface, and which, descend- ing, divides the lateral ventricles into two cavities. After reflecting the corpus callosum, and dividing it across behind, note the condition of the following structures seriatim : — a. The caudate nuclei or intra-ventricular portions of the corpora striata. b. Septum lucidum, enclosing betwixt its walls the fifth ventricle. c. Exposed anterior tubercle of the thalamus opticus. d. Stria cornea, or exposed part of the taenia semi- circularis, coursing between the thalamus and corpus striatum. €. Fringed margins of the velum interpositum or choroid plexus of lateral ventricles. /. Fornix, and behind its descending pillars, the fora- men of Monro. (/. Greneral condition of lining membrane or ependyma. 3. Divide the fornix anteriorly close to its descending pillars, and after examining the subjacent velum inter- positum, reflect both structures backwards, exposing the thalami optici, separated by the intervening third ventricle, and note the condition of the following parts : — a. Grey matter forming the boundaries of the central cavities. b. Anterior, middle, and posterior commissure. c. Pineal gland, and its ganglionic extensions, or peduncles. d. Corpora quadrigemina (nates and testes). e. Follow out the fornix posteriorly into the descending cornua of the ventricles. REMOVAL AND DISSECTION OF THE BRAIN. 73 4. On separating the occipital lobes from the cerebellum the curved bistoury may, by a little careful dissection, be made to cut through both crura cerebri obliquely upwards, to meet above the corpora quadrigemina at an obtuse angle in the third ventricle in front of the posterior commissure. By so doing we separate from the cerebrum the cere- bellum, pons, and medulla, together with the corpora quadri- gemina and pineal gland intact. This method is certainly preferable to dividing the cms at the level of the superior cerebellar peduncle, which is so often done at the sacrifice of the normal relationships of most important regions. 5. Separate the cerebral hemispheres by median section through the slight remaining connections, and proceed as follows : — a. Slice one of the hemispheres in a direction parallel to the sections already made when exposing the centrum ovale. Let numerous sections in this direction be made at different planes from above downwards through the whole hemisphere, so as to expose the structure of the thalamus and corpus striatum down to the base. b. Slice the remaining hemisphere in a direction at right angles to its long axis, or, in other words, from above downwards, beginning our sections near the olfactory bulb, and proceeding as far back as the occipital lobe. These sections {a and b) will familiarize the student Avith the relationships and coarse structure of the basal ganglia — ■ points of considerable moment. Examine, therefore, by aid of these sections, the medvdlary tracts forming the internal and external capsules, the lenticular and caudate nucleus of the corpus striatum, the thalamus opticus and its various regions and environment. All these parts may be studied in suc- cession, referring to good illustrations, such as appear in the last edition of Uuain's "Anatomy." The intimate structm-e and relationships of these regions will be dealt with fm-ther on. 74 COARSE EXAMINATION OF THE BRAIN. 6. Remove the cerebellum from its attachments bj dividing the three peduncles, and proceed to examine suc- cessively — a. Superficial aspect of membranes covering pons and medulla, h. Condition of blood-vessels and superficial origin of the cranial nerves. c. Condition of valve of Vieussens, aqueduct, and fourth ventricle. d. By transverse sections expose structure of nates and testes, of the pons, its anterior, or motor, and pos- terior or tegmental tract, of the medulla oblongata, noting the relative dimensions and appearance of the olivary bodies, the pyramidal and restiform tracts. 7. Lastly, after examining the lobules and membranes of the cerebellum, we divide it into an upper and lower half by an incision carried through both hemispheres from behind forwards, exposing the central medulla. Vertical section — i.e., at right angles to the lamina of the cerebellum — will display its foliated aiTangement, and betwixt vermiform process and the middle of each hemisphere we pass through the plicated corpus dentatum. CHAPTER VI. SUPERFICIAL TOrOGRAPHY. Since the prosecution of researches into the minute anatomy of the brain will necessarily lead us into structui'al details of infinite diversity (for the complete histology of the human cortex cerebri is infinitely more complex than any of our classical works on this subject would lead us to conceive), we shall have to bestow a predominating share of our attention upon cerebral localization. Hence at the outset it is essential that we obtain clear and defiuite ideas of the various sub- divisions of the brain, both as regards convolutionary arrangement and central medullated fasciculi. A knowledge of the convolutions and sulci must be immediately acquired, and from this superficial topography we learn readily to appreciate the relative positions of those smaller areas which, from experimental data, have been proved to possess diversi- fied functional endowments, as well as those cortical tracts which histological inquiry has invested with structural peculiarities. It is not within the scope of this manual to give even an outline of the internal medullated structure of the brain, but it may prove of service here to indicate Professor Turner's nomenclature of the convolutions which, from its great simplicity and clearness, has found such general favour.^ For minute details as to the course, relationships, and devia- tions of these gyri, the student is referred to that very 1 "The Convolutions of the Human Cerebrum Topographically Con- sidered," by William Turner, M.B. Lond., F.R.S.E. Ediu. Med. Jnuyn. June, 1866, 76 COARSE EXAMINATION OF THE BRAIN. excellent translation of Ecker, " On the Convolutions of the Human Brain," by J. C. Gralton. From this work, with the editor's kind permission, I have tabulated the various English and foreign synonyms, as likely to prove of value in the fui'ther prosecution of our studies in this department. The photographs from Bischoff's work on the Convolutions are intended for immediate reference in the laboratory. GENERAL REFERENCE TO THE PHOTOGRAPHS. I. Frontal Lobe. II. Paeietai Lobe. III. Occipital Lobe. IV. Tempoeo-sphenoidal Lobe. 4. 6. 7. 9. 11. 12. 13. 14. 10. 16. n7. Superior Frontal Gyrus Middle Frontal G-yru3 , . Inferior Frontal Gyrus ) Separated by the Supero- frontal j Sulcus. Separated by the Infero -frontal Sulcus. Separated by Rolando. the Fissure of Separated by the Intra-parietal Fissure. External Orbital Gyi'us. Ascending Frontal Gyrus Ascending Parietal Gyrus Postero-parietal Lobule Supra-marginal Lobule Angular Gyrus . . Third and Fourth Annectant Gyri. First Annectant Gyrus. Quadiilateral Lobule .. \„ ,,, ,, t, it. n a • r» • -i 1 r Separated by the Internal Pa Cuneus, or Superior Occipital \ ^, ^ •_;i„i a ,i„„„ ^1 Separated *j I Fissure. Lobule . . Lingual Gyrus rieto- occipital Sulcus. by the Calcarine *18. Fusiform Gyrus / 19. 20. 21. 22. 5. 23. Superior Temporo- sphenoidal Gyrus Middle Temporo -sphenoidal Gja-us Inferior Temporo-sphenoidal Gyrus ) Uncinate Gyrus . . . . j Median Aspect of Superior Frontal \ Gyrus . . . . . . . . f Convolution of the Corpus Cal- ( losum . . . , . . , . / Separated ty the Collateral Fissure. Separated by the Parallel Fissure. Separated by the Collateral Fissure. Separated by the Calloso-mar- ginal Fissure. N.B.— At the Base No. 2, 3, 4, indicate respectively the Internal, Posterior, and External Orbital Gyri. I need scarcely add that the darker and lighter shading of the brain, as shown in the photographs, is well calculated to bring into strong relief the moi'e distinctive areas and divisions of the surface. The relative areas occupied by difierent lobes over each aspect of the hemisphere are thus better displayed than by outline figures, whilst the distinctive character of the gyri is not interfered with. » Neither of these terms is included in Turner's nomenclature. They are adopted by Ecker. LIST OF SYNONYMS FROM ECKER. ADAPTED TO TURXER S NOMENCLATURE. SuPERioB Feo^jtal Gyeus. Erste oder obere Stirnwindung . . . . {Ecker.) Etas'e frontal superieur ou troisiSme . . ) ,^ ^- , ^ \ ° \ [ {Gratiolet.) Pli de la zone externe . . . . . . . . ) Supero-fi'ontal gyrus . . . . . . . . {Rnxlei/.) Middle Feontal Gyeus. Zweite oder mittlere Stirnwindung . , . , {Eclrr.) Etage frontal nioy en .. .. .. .. {Gratiolet.) Medio-frontal gyras . . . . . . . . [Huxlcij.) Infeeior Feontal Gyeus. Dritte oder untere Stirnwindung .. .. {Ecker.) Pli frontal infferieur ou premier ou etage surcilier .. .. .. .. ,. {Gratiolet.) Infero-frontal gyrus . . , . , . . . {Huxley.) Ascending Feontal Gyrus. Vordere Centralwindung .. ., .. {Rusckke.) Processi enteroidei verticali di mezzo (anterior part) . . . , . . . . . . . . {Rolando.) Circonvolution transverse parietale anterieur (Foville.) Premier pli ascendant . . . . . . . . {Gratiolet.) Antero- parietal gyrus . . . . . . , . {Huxley.) SUPEEIOR TEMP0E0-SPHEN0ID.\i GyRUS. Erste obere Schlilf enwindung . , . . ( Wayiier. ) Antero-temporal . . . . . . . . {Ha.dcy.) Pli temf)oral superieur ou.. .. ..\ Pli marginal posterieur ) {Gratiolet.) Gyrus temporalis superior sive infra marginalis {Huschke.) Middle Temporo- sphenoidal Gyrus, Zweite oder mittlere Schlafenwindung Mittlere Schlafenwindung ( Wagner.) {Hi/achkr.) LIST OF SYNONYMS FROM ECKER. 79 Pli temporal moyen ou partie descendante du pli courbe . . . . . . . . . . {Gratiolet.) Medio-temporal gyrus .. .. ... {Huxhij.) Inteeiok Tempoho- sphenoidal Gyeus. Dritte oder imtere Schlaf enlappenwindung i Gyrus temporalis tertius sive inferior . . ' Lingual Lobule. TJntere innere Hinterhauptwindungsgruppe Lobulus LinguaUs — Zungenlappchen Gyi-us occipito -temporalis mediaUs . . Fusifoem: Lobule. Untere aussere Hiuterhauptwindungszug . . Gyrus occii^ito-temporalis lateralis . . Spindellappchen . . Lobulus fusiformis — Spindelformiges Liippchen. Ascending Pakietal Gyrus. Ilintere Centralwindung Processi enteroidei verticale di mezzo (posterior segment) . . . . . . ■ Cu'convolution tranverse medio-parietale . . Deuxieme pli ascendant Postoro -parietal gyrus PosTERO- Parietal Lobule. Oberes Scheitellappchen Gyrus parietalis superior Lobule du deuxieme pli ascendant . . Erste Sclieitellappen-windung Obere Sclieitelbeinlappen Obere innere Scheitelgruppe . . Supra- Marginal Lobule. Dritte Scheitellappenwindung Unterzug aus der hintern Centralwindung ) ScheitelhiJckerlappclien . . . . . . ' PU marginal superieur Erste oder vordere Sclieitelbogenwindimg . . Angular Gyrus {Huxleij). Unteres Scheitellappchen (posterior part) . . Zweite oder mittlere ScheiteUappenwindung Auf steigende "Windung zum hintern aussem j Scheitellappchen und Hinteres iiusseres Scheitellappchen \ ( Wagner. ) (Bisc/wf.) [Htischke.) {Panschand EcJcer.) {Bischoff.) {Fansch and Ecker.) {Eclcer.) {Hiischke.) {Ecker.) [Rolando.) {Foville.) [Gratiolet.) [Huxleij.) {Ecker.) {Punsch.) [Gratiolet.) { Wagner.) [Huschke .) [Bischoff.) [Wagner.) {Huschke.) {Gratiolet.) {Bischoff.) {Ecker.) { Wagner.) {IluscJike.) 80 COARSE EXAMINATION OF THE BRAIN. Zweite odei' mittlere Scheitelbogenwindung [BiscJioff.) Pli courbe .. .. .. .. ,. {Gratiolet.) Quadrate Lobule (Ricrley.) Vorzwickel Lobule quadrilatere Prsecuneus {BurdacJi.) (Foville.) {Burclaeh.) Convolution of Corpus Callosum. Gyrus Fornicatus — Bogenwulst Gyrus cingiili Zwiuge or Cingula Callosal gyrus . , Circonvolution de I'ourlet Processo enteroidio cristato . . {Arnold.) {Burdach.) {Huxleij.) {Foville.) {Rolando.) Uncinate Gyrus {Huxley — Turner). Gyrus Hippocampi Subiculum Cornu Ammonis Circonvolution a crochet Pli Unciforme . . Temporal moyen interne Lobule de riiippocampe Dentate Gyrus. Coi-ps godronne . , CuNEUS {Burdach, Turner, etc.) Zwickel . . Erste oder Hinterhauptlappenwindung Oberer Zwischensclieitelbeinlappen . . Lobule occipital Internal occipital lobule First Annectant Gyrus. Erste oder obere HinterhauptAvindung Oberer Zug der liintern Ceutralwindung . . Erste obere Hinteiiappenwindung . . Obere innere Scheitelbogenwindung Fir^t external annectant gyrus Pli de passage superieur externe . . . . ) Pli occipital superieur . . . . , . . . j {Burdach.) {Burdach.) { Vicq d'Azi/r.) {Gratiolet.) {Gratiolet, etc.) {Echer.) {Wag)ier.) {Huschke.) {Gratiolet. ) {ff/aiei/.) {EcJ.-er.) {Huschke.) { Wagner.) {Bischnff.) {Huxletj.) {Gratiolet.) Second Annectant Gyrus. Zweite oder mittlere Hinterliauptwindung. . Zweite mittlere Ilinterlappenwindung Pli occipital moyen . . . . . , , , ) Deuxieme pli de passage externe . . . . j Gyrus occipitalis medius {EcJcer.) ( IVac/ncr.) {Gratiolet.) {Pansch.) LIST OF SYNONYMS FROM ECKER. 81 Medio -occipital and second external an- nectant .. .. .. .. .. {Huxley.) Third and Fourth Annectant Gyei. Dritte oder untere Hinterhauptwindimg . . {Echer.) Dritte untere Hinterlappenwindung .. {Wagner.) Pli occipital inferieur . . . . . .\ Troisieme et Quatrieme pli de passage ^ {Gratiolet.) exteme . . . . . • . . . . ' Gyrus occipitalis inferior .. .. .. (Pause h.) Lobes of the Ceeebeum. Frontal Parietal . . Temporo-splienoidal . . Occipital . . Central Lobe = Scheitellappen. = Stiralappen. = ScMafenlappen.i Keilbeinlappen . ^ Schlafen-KeQbeinlappen. ^ = Hinterhauptlappen. = Zwiscbenlappen. Versteckterlappen. Centrallappen. Stammlappen. Insel. 1 •= Temporal Sphenoidal. ■* - Temporo-sphenoidal. Fig. 4.— convolutions of the cerebrum, as seen AT THE VERTEX (after Bischnf). Fig. 5.-CONVOLUTIONS OF THE CEREBRUM, AS SEEN AT THE MEDIAN ASPECT (after Bischof). ^ ^ \ \ ^r^ ^ir- -<. kV y KlG. 0.— CONVOLUTIONS OF THE CEREBRUM. AS SEEN AT THE BASE (nficf BUchof). KIG. -CONVOLUTIONS OF THE CEREBRUM, LATERAL ASPECT (after Bischof). PART II MINUTE EXAMINATION OF THE BRAIN G 2 CHAPTEE VII. THE METHODS OF RESEARCH, Prior to considering in detail the methods adopted for the minute examination of the brain, the student should be fully impressed with the conditions which render many of the processes applicable for other tissues quite inadmissible here. The consistence of cerebral tissue is such that cutting fine sections by the hand, either with an ordinary razor or the Valentin blades, cannot be adopted with any hope of success, since the finest sections thus obtainable are useless for micro- scopic examination, which requires sections of extreme tenuity. These extremely fine sections can only be obtained by aid of the screw microtome from portions of hardened or frozen brain. In order to modify the consistence of the tissue so as to adapt it for this purpose, various methods of hardening by chromic acid, chromic salts, alcohol, picric acid, and osmic acid have been devised. The results which have accrued from these methods have been most valuable, yet they are uniformly open to the serious objection that this altered consistence induced by the req.gent is obtained at the expense of modified structure and altered relationships. Amongst the most serious drawbacks to the use of corrugating reagents in the examination of the brain are the following : — A considerable expenditure of time (from three to eight weeks being requu-ed for satisfactory hardening). The process itself is extremely tedious, and often unsatis- factory in its results, as evidenced by experienced histologists. 86 MINUTE EXAMINATION OF THE BRAIN. It requires a considerable amount of practised manipula- tion, and exposes the tyro to numerous disappoint- ments and failures. The shrinldng of tissue is a most objectionable feature in the cortex, often a,mounting to one-half the original bulk. The normal wealth of structm-e is greatly modified; in this respect it is infinitely surpassed by fresh methods. The absolute and relative depth of the various layers of the cortex is subjected to most objectionable modifica- tions. It affects the cortex of different animals to a different extent, thus interfering with comparative investiga- tions. Many pathological and normal aj)pearances are wholly obliterated by the " hardening processes." Of all tissues, that of the brain, from its extreme delicacy and susceptibility to rapid post-mortem change, is the tissue which, above all others, demands a rapid, ready, and fresh method of preparation, the employment of indifferent media, and the restriction of all corrugating reagents. No method as yet adopted can surpass for elegance, expedition, and certainty the freezing method ; and, above all, it is f/w method which should be chiefly trusted to in all exact anatomical and pathological research. Yet, whilst we claim for the fresh freezing methods such self-evident advantages over the older process, the long series of objections to the latter tabulated above must not induce us to blind our eyes to the fact that it also possesses its own advantages and cannot be dispensed with. Most of our classical descriptions of cerebral structure refer to brain which has been subjected to these methods of preparation ; and few indeed, far too few, are the delineations of the minute structiu-es of the cortex and medulla in the perfectly fresh brain. Hence, as a question of simple comparison between the results of different observers and our own, the hardening methods must still be adopted. There are numerous other very apparent reasons THE METHODS OF RESEARCH. 87 ■why we cannot afford to dispense with the older processes, and the student is therefore recommended, whilst guarding himself from its fallacies, checking or confirming its results by the fresh methods, to make himself equally familiar with the practical details of both methods, and to learn to discriminate the special work to which each process is more particidarly suited. Two Distinct Methods of Freezing. — Just as we find amongst the list of reagents used for hardening brain, some, and especially osmic acid, far less open to the objectionable qualities possessed by alcohol and chromic acid, inducing in fact very slight alteration in the relationships and bulk of the tissue, so do we find the different methods of freezing- possess their o^vn distinct and relative merit. This fact, which it is all-important to recognize when dealing with structures like the brain, has been wholly misunderstood or overlooked by all authorities who have written upon the subject, and we constantly find histologists grouping the freezing by ice and salt with the ether freezing method, as though both were equally suitable for all tissues alike. Now the fact is that the ordinary ice and salt freezing micro- tome is entirely useless for brain-structures, except after a modification of the latter by a process of hardening, and hence no longer a fresh method. Upon the other hand, the ether freezing microtome is applicable to all tissues having a consistence not above that of the liver, but is pre-eminently adapted for nervous tissue. I find it necessary to insist upon this point, since it seems generally understood that the ice and salt mixture is suitable for freezing brain. Prior to the introduction of freezing by ether, practised liistologists con- stantly complained of the impossibility of obtaining fine sections of brain by freezing, the objections being that hard spiculse formed within its structm^e, and tore it up on cutting through it. Yery lately this fact has been again asserted by a skilled manipidator,^ who has even introduced a method of ^ Vide Hamilton in the Journ. Anatomy and Fhys. vol. xii. p. 259. 88 MINUTE EXAMINATION OF THE BRAIN. combined hardening and freezing to overcome this very unsatisfactory action. Hitherto, therefore, it may be asserted that the use of the ice and salt microtome has failed for the purposes of the cerebral histologist ; and although by further development it may be rendered sub- servient to his purposes, for the present the freezing of brain-substance must be uniformly pursued upon the ether freezing microtome. The methods available for the exami- nation of the minute structure of the brain are as follows: — Hardening processes for sections to be cut on the imbedding microtome. Hardening processes for sections to be cut on the freezing microtome. Fresh process by means of the ether freezing microtome. Fresh process by a modified teazing and staining. Fresh process by ordinary teazing with dissociating reagents. We will preface our account of these methods by a brief outline of the more useful microtomes used. CHAPTER VIIL microtomes for imbedding and freezing. Microtomes for Imbedding. Amongst the various instruments devised for cutting sections of hardened tissues are the microtomes of Henson, Rivet- Leiser, Brandt, Roy, His, Ranvier, Stirling, and Rutherford. The instrument more generally used in this country is that devised hy Stirling, and its modification by Rutherford, either of which instruments will prove satisfactory to the student ; whilst that of Ranvier may be employed where it is desirable to grasp the microtome in the hand, or immerse it during section-cutting in water or spirit. The principle adopted in Stirling's instrument has been very generally followed. In the last three named, the body of the instrmnent consists of a metal tube or hollow cylinder, fixed to a table by some simple arrangement, or held in the hand in an upright or vertical position. A fine micrometer- screw works into the lower end, driving through the hollow of the cylinder a closely-fitted piston-plug, which in its turn propels the mass in which the tissvie to be cut is imbedded. The essential portion of this form of microtome, therefore, is the body or cylinder, and the powerful micrometer-screw. The body, or cylinder, includes the following divisions: — the hollow, or " well " of the cylinder ; its closely-fitted plug, or "piston ;" the upper smooth and levelled extremity, or " section-plate ;" the lower extremity forming a " female screw " for the reception of the micrometer-screw. It is far preferable that the cylinder should be clamped by projecting 90 MINUTE EXAMINATION OF THE BRAIN. arms and screw to a firm support as a table. In choosing a microtome for cutting sections of an imbedded tissue tbe student must be guided by the following considerations. The instrument should be strong but compact, and not weighty or cumbersome ; it should possess appliances for fixing it firmly and immovably to a supporting ledge or table. Its well should be at least one inch in diameter, and the oval section is to be preferred to the circular well, since this form of well wholly prevents rotation of the imbedded mass. The section-plate should be absolutely level, perfectly smooth, polished, and show no irregularities of sm^face or indentations around the margin of the well, which otherwise would ruin the edge of the blade. The micrometer-screw should be of powerful leverage, work evenly, easily, and without the slightest " loss of time," and have a pitch of at least fifty threads to the inch. Allowing his judgment to be guided by the above rules, the student cannot err greatly in his selection of a microtome for ordinary work and the smaller class of sections. A few words on the different varieties of instruments used may prove of service to the student. 1. Stirling's Microtome is a compact, strong, and admirably finished instrument, embracing all the qualities essential for the section-cutting of hardened preparations. For small sections no better adapted form has yet been devised, and for his earliest attempts in cutting hardened brain the student is recommended to secui-e this form of microtome. This instrument is made to be clamped to a table, so that both hands are free for section-cutting. 2. Ranvier's Microtome, — This is a smaller but very useful instrument. It has, however, to be held in the hand, a defect which is in part counterbalanced by the ease with which it can be immersed in spirit, and sections cut whilst so situated. It is well adapted for sections of spinal cord and the large nerve-trunks. 3. Rutherford's Microtome. — This, which is a modified form of Stirling's microtome, is a most valuable instrument, MICROTOMES FOR IMBEDDING. 91 as it is well adapted for section-cutting of imbedded or of frozen tissues. It will be described fully in the section on freezing microtomes. It has the disadvantage of being some- what cmnbersome as compared with the smaller " Stirling," whilst at the same time as a freezing instrument for nervous tissues it is excelled by the ether freezing microtomes. The latter remark does not apply to other animal tissues. 4. Roy's Microtome^ consists of an inner vertical brass plate covered with a layer of cork, and sHding by vertical movement within an outer brass frame-work. A glass rod of horse-shoe form is fixed horizontally by its extremities into the brass frame, upon which the blade glides during section-cutting. The imbedding mixtm^e is first cast in a zinc mould, the tissue being placed in it, and when hardened, the mass is fixed upon the cork plate. The vertical movement of the brass slide is obtained by propulsion from a fine-threaded screw fixed below. A simple tubulature, adapted to the instrument, allows spirit or water to be blown upon the mass when requii-ed. It has been stated that tissues may be cut fresh with this microtome after freezing by the direct appli- cation of the ether spray. The student must be cautioned against any such attempt; for all tissues alike, the dii"ect application of ether is to be deprecated, and for brain and spinal cord and all nervous structures such a method is wholly inadmissible. Eoy's microtome has the disadvantage of not being readily fixed to a table during manipulation. " 5, Schiefferdecker's Microtome is described here as appUcable to hardened preparations, although it is essentially constituted to dispense with the method of imbedding. The object to be cut is fixed within a hollow brass cylinder by means of a clamp upon its surface worked b.y two screws. In lieu of a propelling screw below, as in other microtomes, a circular plate forming the section-plate can be elevated or lowered by the revolution of an outer concentric plate which 1 Described and figured in the Journal of Physiology, vol. ii. No. 1. 2 Tlie instrument is made hy Mr. Gardner, South Bridge, Edinburgh. 92 MINUTE EXAMINATION OF THE BRAIN. turns upon a screw. The student will find this microtome figured and described in the Qiiarterhj Jownial of Micro- scopical Science for January, 1877. 6. Microtome for Slicing through Whole Hemi- sphere of Human Brain. — The instrument which I have had made for this purpose at the West Riding Asylum consists of a heavy brass cylinder, 3 inches deep and 8 inches in diameter, closed in below, where, however, its cavity com- municates centrally with that of a small secondary cylinder — the screw-socket. In this socket, which is 4 inches deep, works a powerful and finely-threaded screw, having a milled head 3 inches in diameter. A flat, circular brass plate, accm'ately fitted to the interior of the upper cylinder or well, is raised or lowered by means of the screw, the movement being communicated to the imbedding mass, which rests upon it above. The section-plate is constituted by the projecting rim of the cylinder above, and is mathematically level and smoothly polished. The microtome rests upon the iron collar of a powerf id tripod stand. A zinc tray, 2\ inches deep and 26 by 17 inches, can be adapted to the microtome- cylinder, so that sections may be cut under water with the greatest ease. Microtomes for Freezing. 1. The Ether Freezing Microtome (Bevan Lewis). — This microtome was described in the Journal of Anatomy and Physiology for April, 1877, but has been modified and improved in several resjDects by the present maker. ^ It consists essentially of «, the body ; h, the freezing chamber ; c, the section-plate. a. The Body. — This is really a modified " Stirling micro- tome," and forms the lower half of the instrument. Through its central aperture works a brass plug, driven by a strong but fine micrometer-screw. In my own instrument, the pitch ' The improved microtome may be obtained of Mr. Gardner, 45, South Bridge, Edinbvu'gh, who, at a minimum of charge, has fully perfected the woi'kmanship. Descriptions of the microtome may be also found in Brain, October, 1878; and in Dr. Stirling's " Text -book of Practical Histology." MICROTOMES FOR FREEZING. 93 of the screw is fifty tlireads to the inch ; the screw has a diameter of ---inch, with a milled head, Ih inches across. A coarse screw secures the body of the instrument to a table. b. The Freezing Chamber. — This consists of a zinc cylinder, closed above and below, pierced on either side by a large Fig. 8.— The Ethee Freezing Microtome. (Original Model.) aperture, to allow of the admission of the nozzle of the spray- producer, as well as to permit free evaporation of ether, much of which, however, condenses on the bottom, and is conveyed off by the bent tube into a bottle attached to it. I have found it convenient to have the zinc cylinder quite 21 inches wide by Ih inches deep, and the aperture in the side of the instrument f -inch in diameter. The cap or plate closing the cylinder above, I term the freezing plate, and upon it rests the tissue, whilst the ether spray plays upon the plate from below. The freezing- chamber is thus rapidly reduced in temperature, and to pre- vent conduction by means of the section-plate, it is well to have a free interval all around the freezing cylinder, securing it from actual contact with the section-plate. 94 MINUTE EXAMINATION OF THE BRAIN. c. The Section-Plate. — This is made either of metal or of plate-glass, drilled with a central aperture, through which the freezing chamber glides. If of metal, it should, by prefer- ence, be made of a smooth, polished zinc plate, about -f -inch thick, supported by strong vertical arms upon the body of Fia. 9. — TnE Ether Freezing Microtome. (New Form.) tlie instrument. I would strongly advocate the use of the plate-glass, since it renders the movements of the knife abso- lutely free and easy ; whilst, on the other hand, the blade never gets injured from scratches, which, sooner or later, invariably appear upon a metal section-plate, and wliich turn or indent the edge. MICROTOMES FOR FREEZING. 95 To recapitulate — the various divisions of our microtome are as follows : — a. The "body," comprising the "well," the "piston," and the " micrometer-screw." h. The " freezing chamber," fitted with sloping false- bottom, an " exit-tube," and capped by the " freezing plate." c. The "section-plate," drilled for the passage of the " freezing chamber." The Freezing Medium. — The best anaesthetic ether should be employed. I find it more economical than methylated ether. The ordinary Richardson ether spray is the more generally used instrument ; but a further improve- ment has been introduced by the maker, in the form of a lateral support for the ether-spray apparatus, communicating with a bellows worked by the foot. In this form, the spray adjustment is easy, and the hands are both free for section- cutting and manipulation, and thus a most substantial and valuable improvement has been obtained, with but a very trifling addition to the cost of the microtome. 2. Rutherford's Freezing Microtome.^ — This instru- ment consists of a brass section-plate, with a central aperture leading into the interior of a vertical tube, in which a plug is fitted to move upwards or downwards by means of a fine screw. The cylinder is surrounded on all sides by a metal box covered with gutta-percha, which holds the freezing mixture of ice and salt. An exit tube allows of the escape of water. The whole instrument can be securely clamped to a table. The method of using this instrument for freezing is as follows : — The plug is first unscrewed and oiled, so as to prevent its fixture clming the process of freezing. The tissue to be frozen and cut is first immersed in a thick ' "A New Freezing Microtome:" Monthly Micros. Journnl, vol. x. p. 185. "Outlines of Practical Histology : " by William Rnlherford, M.D. 2ncl edit. p. 164. 96 MINUTE EXAMINATION OF THE BRAIN. solution of gum for some hours, " in order that the gum may permeate every part of the tissue, and prevent the formation of a crystalline condition within the frozen tissue." If the tissue has been previously immersed in alcohol, all traces of the latter shoidd be first removed by soaking in water. Equal parts oi finely-powdered ice and salt are now placed in the freezing box and stirred around the well, whilst the latter is filled with the solution of gum. As the gum freezes around the periphery, the tissue is plunged into it, and held Fig. 10. — Exttherford's Freezing Microtome. until it is fixed by the advancing ice. Care should be taken to keep the exit-tube of the box open, so as to allow of free escape of water, and to close the freezing box by a weighted strip of cork, to prevent the entrance of heat and to exclude the salt of the freezing mixture. By this method the freez- ing process may be accomplished in from ten to twenty minutes. All delicate tissues require a sipecial prejmrofion to adapt them for this process, otherwise the water which they contain freezes into hard icy spicules, whicli tear the structure MICROTOMES FOR FllEEZTXG. 9T when it is cut. Dr. Pritchard has therefore recommended a prior immersion of the tissue in thick solution of gmn-arabie, using the same solution as the imbedding material. Quite recently, Dr. Hamilton whites as follows with regard to freezing the nervous structures, and especially brain, by means of the ice and salt microtome. " It was found that the crystals of ice so broke up the delicate nervous tissue as to render it totally useless for minute examination I attempted two years ago to modify the method of freezing, but without success, and accordingly gave it up as an almost hopeless task." ^ According to this statement, the writer's exi^erience tallies wholly ^^'ith my own ; and f idly acquainted as he was with the methods of steeping tissues in gum prior to freezing which were adopted by Dr. Eutherford, it is clear that this method of freezing was not applicable for fresh brain, although it answers admirably in the case of firmer and less delicate textm-es. Dr. Hamilton overcame the difficulty of freezing brain with the ice and salt mixture, but at the expense of sacrificing the fresh for the chrome hardening process, a special procedure being requisite, which will be considered further on. Now it is after such considerations that we recognize the undoubted superiority of the ether freezing microtome for nervous structures. It has been stated that the ether freezing process has been entirely superseded by the introduction of ice and salt, or other mixtures, which by con- stant refrigeration keep the mass in a frozen state for houi's. All practical manipulators, however, know that this is, as regards nervous structures, a fallacy and a blunder, since the very excellence of the ether freezing method depends upon the fact that it can be checked at any stage and renewed when required. This is the all-important consideration in freezing brain, for beyond certain limits it is frozen into a hard icy solid, which at once blunts or tm-ns the edge of the blade ; but with the ether-spray this stage need never be attained, and a consistence is obtained admirably adapted for ' Jonrti. of Aiuif. and riiijs. vol. xii. p. 257. H 98 MINUTE EXAMINATION OF THE BRAIN. section-cuttiug. The student should therefore bear in mind that the constant cqyjjiication of a freezing mixture to fresh brain cannot but result in failure for section-cutting ; and that bi/ use of the ether process the prior jnrparation of brain by hardening, or by immersion and saturation in mucilaginous fluids, may be wholly dispensed irith. 3. Williams' Freezing Microtome.^ — In this instru- ment a wooden tub containing a freezing mixture of ice and Fig. 11.— Williams' Freezing Miceotome. salt is covered by a glass lid, the frame of which is seciu-ed by a clamp screw. An upright brass conducting-bar passes from the interior of this box through a central apertm-e in the lid, and to the extremity of this bar is screwed the circular brass plate which supports the tissue to be frozen. The arrangement of the knife is peculiar, since it is fixed in 1 This instrument is made by Messrs. Swift & Son, University Street, London. MICROTOMES FOK FREEZING, 99 a triangular frame, and can be either raised or lowered by the screws which are adapted to the frame. There are three additional plates for supporting the frozen object, and a brass cup for holding substances, which are fixed in cacao-butter or paraffin. The box is filled with equal parts of pulverized ice and salt, care being taken to prevent the mixture touching and so fixing the cover. After the cover is replaced and screwed down, the substance to be cut is placed on the central brass plate, surrounded by a little solution of gum, and the appa- ratus is covered with baize to facilitate freezing. When frozen, raise the blade, and after the fii'st cut across, proceed as follows : — Each end of the razor must be presented to the surface of the section, and exactly levelled by means of each of the hack screws. If the large back screw be now tiu-ned, the blade can be lowered to any required extent ; and since a complete revolution of the screw gives us a section -p^-jy-inch in thickness, and the screw-head is graduated into sixths — a movement through sixty degrees gives us a section ^-^p-inch thick. The special featm'es of this microtome, in which it differs materially from others already described, consist in an arrangement whereby the blade and not the imbedded or frozen tissue becomes the movable part of the instrument ; and the edge of the knife is only brought into contact with the substance to be cut. h2 CHAPTER IX. PREPARATION OF HARDENED BRAIN. In subjecting the brain to the agency of hardening reagents certain important conditions should always be kept in mind, as they are essential to success. The conditions are as follows : — a. The reagent should act equably upon all portions of the tissue. b. The requisite consistence must be acquired at the expense of the minimum of alteration and shrinking of tissue. Now the fii'st of these conditions can only be obtained by ensuring a thorough saturation of the tissue throughout, so that the fluid permeates rapidly to the central or deepest portions of the mass. It is evident that the surface of the tissue being bathed in the reagent will be more actively affected by the latter than the more distant parts within, and thus arises the danger of a too rapid hardening of the exterior, which forms a mechanical impediment to the per- meation of the deeper structures by the surrounding fluid. Always, therefore, take the precaution to ensure a free and rapid permeation of the tissues by the fluid. Again, if any portion of the surface is in close contact with the side of the containing vessel, it necessarily is less affected than the surface bathed in the fluid. The mass should there- fore be so suspended that it is equably bathed all around in the reagent. PREPARATION OF HARDENED BRAIN. 101 Another important consideration is that of temperature, for under the most favourable cii'cumstances the central or deeper structures must remain far less subject to the action of the reagent than the exterior of the mass, and are, therefore, the parts which most readily succumb to putrefactive changes. The larger the mass, therefore, to be hardened, the moi'e difficult is it to prevent central decay, whilst an elevated temperatui'e induces the same result. The tissue to be hardened should therefore be of moderate hulk as compared with the fluid in which it is immersed, and the preparation should be kept in a cool spot, or better still, in an ice safe. The next condition we have named, and which it is equally important to secure, is that a minimum of shrinking of tissue should result from the action of the reagent, and it is a well- known fact that all the reagents used for this purpose will, if employed in too concentrated a form, ruin the preparation by inducing extreme shrinking and brittleness of the mass ; whilst again, some of these reagents are far more reliable than others, and less open to these disadvantages. The more commonly used hardening reagents are — osmic acid, Miiller's fluid, solutions of the chrome salts, chromic acid, picric acid, methylated spuits, and alcohol. Now this list represents their relative value as hardening reagents for nervous tissues, osmic acid and Miiller's fluid standing at the head of the series as the most valuable and least injurious in their action, chromic acid and alcohol occupying a far less prominent position in the scale. In order therefore to secm^e the tissue from injurious shrinking, employ in preference to the others the reagents noted at the head of the list, and use the weakest solu- tions compatible with safety to the tissue, commencing with the weakest, and gradually augmenting the strength of the solu- tion, or, later on, even replacing by the more astringent reagents. Let us now detail throughout the process recom- mended to the student for his first essay in chrome-harden- ing, subsequent to which it will be useful to briefly dwell upon the various modifications of the process adopted by others. 102 MINUTE EXAMINATION OF THE BRAIN, § PROCESS OF HARDENING BY CHROME. 1. Miiller's Fluid and Potassium Bichromate. — Excise a portion of the ascending frontal or parietal convolu- tion of human brain, cutting across its length so as to remove about an inch of the convolution along with its central and deeper medulla. Lightly cover it all round with a little cotton-wool, and immerse it in from two to three ounces of methylated spirits contained in a four-ounce stoppered bottle. Label the bottle with the name of the specimen and date, placing it in a cool cellar or ice safe. In twenty-four hours pour away the spirit, replacing it by four ounces of Miiller's fluid, the preparation being sur- rounded as before by cotton-wool to ensure it being bathed upon all sides alike by the fluid. Let the bottle stand in a cool spot, and in three days replace the fluid by a fresh quantity. At the end of one week the fluid should be again renewed, or, preferably, a. weak solution of potassium bichromate substituted (2 per cent.). At the end of the second week a solution of the latter of double the strength may be added ; and if at the termina- tion of the third week the mass is still pliable, and of the consistence of ordinary rubber, it is as yet unfit for section- cutting, and the reagent should be rej)laced by a solution of chromic acid. In these later stages the chromic acid expedites the process without producing the extreme shrinking of tissue which ensues if it be used at earlier stages. For the same reason even absolute alcohol may at this stage be employed, but although valuable in the preparation of the spinal cord, it cannot be equally well recommended for the cortex of the hemispheres. By the above process our preparation will have attained the requisite consistence within a period of from four to eight weeks. It will be observed that in the various steps of this process the conditions previously emphasized as essential to success are obtained. Thus the early immersion in methy- PREPARA.TION OF HARDENED BRAIN. 103 lated spirit abstracts all superfluous fluid from the brain aud its vessels, and entering its substance by its afiinity for water, aids in tbe rapid permeation of the mass by the chromic solu- tion in the next stage. The more prolonged action of the spirit would, however, prove highly detrimental. Again, the cotton- wool ensures an equable distribution of fluid around, whilst the comparative bulk of the mass and fluid in which it is immersed, and the temperature to which it is exposed, provide for equable hardening to its deepest structures, and ensure it against decomposition. The gradual increase in the potency of our reagents from Miiller's fluid to the strong solutions of chrome is also an adjunct to the hardening of the central portions, whilst we also expedite the process of hardening. 2. Potassium Bichromate and Chromic Acid (Eutherf ord) . — Place small portions of the cerebrum in methylated spirit for twenty-four hours, observing the same precautions as to relative bulk of the preparation and the reagent, covering with cotton-wool, and leaving in a cool place. Replace the spirit by a mixture of potassium bichro- mate and chromic acid. The proportions may advantageously be varied, according to the condition of the structure to be hardened ; but the solution recommended by Rutherford, and which answers well, contains 1 gramme of chromic acid and 2 graromes of potassium bichromate to 1,200 c.c. of water. Change at the end of eighteen hours, and then once a week. Should the tissue not be sufficiently tough for cutting at the end of six weeks, place it in a ^ per cent, solution of chromic acid for a fortnight, and then in rectified spirit. 3. Iodized Spirit and Potassium Bichromate (Betz). — Large portions of cerebrum may also be placed for a few hoiu-s in methylated spirit, tinted of a light sherry-brown by tincture of iodine. Add fresh iodine solution as the colour fades. In one or two days remove the pia mater, and return the preparation to the solution, adding to the latter haK its bulk of fresh iodized spirit. After the lapse of another period 104 MINUTE EXAMINATION OF THE BRAIN. of two days, replace tlie solution by iodized alcohol (alcohol 70° — 80°) tinted of a sherry-brown by a tincture of iodine. In from two to three days it should be transferred to a 4 per cent, solution of potassium bichromate until sufficiently hardened for section-cutting. Shoidd a brown deposit form over its surface during the process, let it be well washed, and a fresh solution used. When hardened, these preparations may be kept permanently in 0*5 per cent, solution of bichro- mate. If the cerebellum is to be hardened, the segments are at once placed in the iodized alcohol, adding fresh iodine frequently as the colour of the solution j)ales. Remove, the pia mater on the second or third day, and in a week transfer to pm'e methylated spirit for twenty-fom^ hours, and finally harden it in a '5 per cent, solution of potassium bichromate. This process, recommended by Prof. Betz, is not suitable for examination of the cortex, as the iodized spirit is injurious to the after-processes of staining. It is, however, especially suited for obtaining large sections through the hemisphere, the whole cerebrum and cerebellum, when sliced evenly across into segments |-inch thick, being most satisfactorily hardened throughout. For the minute examination of the cortex methods 1 and 2 are pre-eminently to be preferred. 4. Miiller's Fluid and Ammonium Bichromate (Hamilton). — This method is especially applicable to large segments of the brain, and is much to be preferred to the process by chromic acid, 5. The brain is sliced completely through into segments about one inch thick. Each segment may now be placed in a large vessel, such as a brain-prepara- tion jar, padded with cotton-wool, and containing a com- paratively large bulk of the solution, which consists of three parts of Midler's fluid to one part of methylated spirit. A refrigerator or ice safe should invariably be employed to pre- clude decomposition, and the pieces should be turned over occasionally in the solution. In about three weeks they may be transferred to a solution of ammonium bichromate (•25 per cent.). At the end of the fom'th week replace by a PREPARATIOX OF HARDENED BRAIX. 105 1 per cent, solution of the same salt, and the following week by a 2 per cent, solution, in which they remain until fit for section-cutting. 5. Chromic Acid Solution (Lockhai-t Clarke). — The convolutions of the cerebrum and cerebellum were by tliis process hardened in a 0*25 per cent, solution of the crystallized chromic acid — a stronger solution rendering them far too brittle for section-cutting. As stated above, chromic acid is not adapted for hardening so satisfactorily and uniformly as the chrome salts. This method, emploj^ed by Lockhart Clarke, has been superseded by more reliable methods, as are also the processes recommended by Stilling, Kolliker, Hanover, and Yan-der-Kolk, for the hardening of nervous textm'es. § HARDENING BY OSMIC ACID. It has been already stated that osmic acid (OsO^) is one of the most reliable agents for hardening the brain and other nervous textures which we possess. Prof. Sigm. Exner, of Vienna, has therefore devised a method whereby small por- tions of the brain may be prepared for section-cutting by means of this reagent.^ Exner's Process. — A small portion of brain, not ex- ceeding one cubic centimetre in size, is placed in ten times its volume of a solution of osmic acid (1 per cent.). The solution should be replaced by a fresh reagent of the same strength after the lapse of two days — a proceeding which may be advantageously repeated at the end of the fourth day. In from five to ten days the piece is usually stained throughout, for this reagent has the valuable property of hardening and staining simultaneously. The hardened brain is then washed in water, plunged for a second in alcohol to facilitate the imbedding, and sections are cut in the iisual way in an ' "Zur Kenntniss vom feineren Baue der Grosshimrinde." Aus dem Ixxxiii. Bande der Sitzb. der k. Akad. dcr Wissensch. iii. Abth. 1881. lOG MINUTE EXAMINATION OF THE BRAIN. ordinary microtome. The subsequent treatment of these sections will he given later on, when methods of staining and mounting are considered. It is only necessary here to remind the student that osmic acid is really a most valuable agent in the investigation of brain-structm^e, and he shordd avail him- self of every opportunity of becoming familiar with its action. § SUMMARY OF PROCESSES FOR HARDENING. The student having been thus placed in possession of the more valuable methods for preparing the brain for the imbedding microtome, it will be well to indicate the method he should adopt in his earlier attempts, as each process has its own individual merits. It is advisable that his first attempts should be made with comparatively small portions of tissue — about 3 c.c. in bulk — and that he should employ the process of hardening by Miiller's fluid and potassium bichro- mate. 1. This process, to which I assign the first place amongst the chrome-hardening processes, is slow but very certain. The results are, to my mind, more satisfactory than those of any of the other methods, and I invariably adopt it myself as the one for general use at the West Riding Asylum. The vessels which the student will find most convenient to use for harden- ing these smaller portions of tissues are the stoppered glass bottles of 4-oz. capacity employed for dispensing purposes. Each bottle should be labelled with the name of specimen and date and nature of each successive change of reagent, whilst the specimen should occasionally be removed, and its con- sistence noted so as to familiarize the touch with the increas- ing firmness of the tissue, and the degree of hardness requisite. The method recommended by Rutherford (2) is also very reliable for moderate-size specimens. The methods advocated by Betz and Hamilton (3, 4) are peculiarly well adapted for large segments of the brain, a whole hemisphere rilErARATlON OF HAKDEXED BKAIN. 107 being thus readily hardened throughout. When these large masses of tissue have to be dealt with, special precautions are requisite. Thus the hemisphere should be sliced horizontally or vertically into segments not over f-inch in thickness. Each segment should rest upon a bed of cotton-wool in the vessel for its reception ; and if two segments are included, another stratum of cotton-wool should be interposed betwixt them. The vessels containing the specimen should be of large size, varying in capacity with the bulk of the latter. Thus a large preparation glass, such as is used for preserving brain in spirit on museum shelves, mil be found well adapted for hardening the whole hemisphere ; whilst pickle-bottles, esjDccially those provided vdth. the " patent lever stopper," are most suitable for the basal ganglia, cerebellimi, smaller por- tions of the cerebrimi and the pons. Still smaller segments, such as the student will have more frequently to deal with, are best hardened in the 4-oz. stoppered bottle, a good supply of which should be kept on hand. All the foregoing processes are contrasted with that of Exner's (osmic acid) in being most adapted for the demonstration of the nerve- cells and plexuses of the grey matter of the brain and its ganglia ; whilst the latter, failing in this respect, is, on the other hand, infinitely better suited for exhibiting the struc- ture of the cerebral medulla and its extensions into the cortex of the brain. The student is therefore recommended to make himself acquainted with the structures of the cortex by the chrome methods, and subsequently to employ Exner's method for demonstrating the medullated tracts of the cortex. § IMBEDDING AND SECTION-CUTTING. Having satisfied himself that the specimen is sufiiciently hard for section-cutting, the student first cuts off a portion which can be accommodated by the well of the microtome, and prepares it for imbedding by a prior immersion for a few minutes in rectified spirits. This removes the fluid derived from the chrome solution from which it has been 108 MINUTE EXAMINATION OF THE BRAIN. taken. In the meantime the imbedding mass should he melted at the lowest temperatm-e requisite. The micrometer- screw should he lowered sufficiently to allow of a deep imbed- ding of the tissue. The preparation is next removed from the spirit, rapidly dried by a fold of blotting-paper, and momen- tarily plunged into the warm imbedding mixtiu'e, which, upon its removal, leaves a film over its surface, whilst all small cavities or lacuna which it may contain are filled up. The melted mass is now poured into the well of the microtome, and the preparation immersed and held in the position re- quired for section-cutting until fixed by the cooled and con- solidated mass. If the imbedding mass is one subject to much contraction on cooling, it is requisite, just as it is becoming " set," to press down with the end of a spatula the margin of the wax and the oil mass against the sides of the well. The Imbedding Mass. — In the process of imbedding, the principle to be remembered is that the mass should be not too resistant to the blade, whilst at the same time it affords efficient support for the imbedded tissue. If the textm-e be one readily permeated by the imbedding mixture, contraction of the latter in cooling is apt to result in injmy to the prepa- ration, more especially if this be one of the more dehcate structures. Thus, in the delicate embryos of the fowl and other similar organisms, special methods of imbedding will be requisite. For the brain and spinal cord, however, the process is comparatively simple, since the imbedding mass neither permeates its structures nor injures it by contracting. The following are the more important media employed for imbedding prior to section-cutting : — 1 . White wax. Olive oil, equal parts. 2. White wax, 3 parts. Olive oil, 1 part. 3. Wliite wax. Cacao -butter. 4. Solid paraffin, 5 parts. Hog's lard, 1 part. 6. Solid paraffin, 5 parts. Paraffin oil, 1 pai-t. Hog's lard, 1 part. 6. Solid paraffin, 5 parts. Spermaceti, 2 parts. Hog's lard, 1 part. 7. Spermaceti, 4 parts. Cacao-butter, 1 part. 8. Spermaceti, 4 parts. Castor oil, 1 part. PREPARATION OF HARDENED BRAIN. 109 The first on this list is perhaps the more generally employed medimn, but it possesses the disadvantage of contracting strongly on cooling, so as to leave an interval betwixt the wax plug and the sides of the well : this, of course, will necessarily tend to loosen the mass, and allow rotatory or " wobbhng " movements, which prevent accurate section- cutting. These disadvantages may be overcome by one or other of the following measures : — Yary the proportion of the oil and wax in favour of the former. When solidifying, press down the edge of the mass with a spatula. Use a microtome plug wdth groove or projections on upper surface. Drive the mass out of the well, partly surround it with a narrow strip of blotting-paper, and return it — forcibly pressing it down into the well — the blotting-paper swells by imbibition of the spirit in section-cutting, and so fixes the plug firmly. In the use of the third medium, viz., white wax and cacao- butter, far less contraction ensues upon solidification, and a firm supporting mass is obtained, the proportion of the in- gredients varj'ing with the firmness required. I can also speak favourably of the combination of paraffin with hog's lard. In all these cases it is well to keep the mass in a small tinned pot with lip, provided with cover and handle, so that it can readily be held over a gas-jet or Bunsen burner, and melted as required. Another imbedding agent used is gum, which is solidified by the application of alcohol or methylated spuits. This method, proposed by Briicke, although valuable for many tissues, cannot be recommended for brain. ^ Imbedding is wholly dispensed with in the form of micro- tome devised by Schieif erdecker, where the preparation having been hardened by alcohol as far as practicable, is placed in the well and clamped firmly by the arrangement already de- scribed. In the small hand-microtome of Eanvier, again, the 1 " Handbook of the Physiological Lahoratoiy," p. 92. 110 MINUTE EXAMINATIOX OF THE HRAIN. ordinary melted media for imbedding are often exclianged for elder-pith, whicli is packed around the tissue in the well in a dry state, and then, upon immersion in spirit, the pith swells and firmly fixes the preparation. None of these latter methods are so suitable for hardened brain as imbedding in the wax and paraffin mixtures. Section-Cutting. — The preparation being satisfactorily imbedded, and the mass perfectly cold and hard, our next procedure is to cut the finest possible sections — they cannot he cut too fine. Place on the table supporting the microtome, and in front of the latter, two vessels, one a Griffin beaker- glass of three inches diameter, and the other a cylindrical glass jar, a brain-preparation jar, or better still, a flat-bottomed porcelain evaporating basin. Nearly fill the beaker with methylated spirit, and the latter with water. Seat yourself in front of the microtome at a convenient level for the free play of the hands, place a soft towel over the knees, to be used for wiping off adherent wax from the imbedding mass. Have close at hand, also, a razor-strop, a porcelain capsule of small size, and some camel-hair brushes. Dip the section-blade in the methylated spirit, and having raised the imbedded mass slightly above the level of the sec- tion-plate, slice off the superficial portion, exposing a clean smooth siu'f ace of the tissue for cutting. Again dip the blade into the spirit, and turning the micrometer-screw, say through one-eighth of a revolution, place the flat of the blade upon the section-plate in front of the mass, with the back towards yourself and the handle in your right hand, grasped near the heel of the blade. Now cut your first section by a clean steady sweep from heel to point, and always aicay from your- self. No saw-like movement should be performed, nor should the blade be arrested occasionally in its course, the section shaved continuously and evenly off the preparation. The thin film of wax removed from the front of the tissue is sometimes likely to get in the way of very fine sections, and hence it is usually advisable, with a penknife to gently PEEPARATION OF HARDENED BRAIN. Ill remove all the imbedding mass in front of the preparation to about the depth of a couple of millimeters prior to section- entting. Subsequent sections should be cut with a still more restricted movement of the screw, until the operator has foimd the minimum degree of movement at which a section can be cut. This, of coiu-se, is a matter of tact, and the student will find that he daily improves the quality of his sections by practical manipulation. Two precautions must ever be taken if successful sections are desii-ed. The first is, that as the blade is raised out of the spirit, the latter should not be drained off, but a good flow be retained over the surface of the blade, so that the section is floated up as it is cut. In the next place make it a rule to pass the blade across the strop frequently, after cutting half-a-dozen sections, as it requu-es to be kept at the flnest possible edge. As the sections are cut they are floated off into the porcelain basin of water, and are freed from adherent particles of the imbedding mass by the rapid gyratory movements they here tmdergo from the euiTents caused by the attraction of water for the spirit they contain. After floating off each section in the water, pass the blade softly over the towel to clear its surface from adherent wax, prior to bathing it afresh in the spiiit. How is the student to ascertain whether his sections be sufficiently thin ? The exact thickness of the section is ascertained if the pitch of the micrometer-screw is known, and the degree of movement which he adopts noted. Thus, if the screw have eighty threads to the inch, a movement through one-eighth of a complete tm-n, i.e., 45°, will give a section ■g-J-Q-inch in thickness, whilst a movement through an arc of 30°, or one-twelfth the entire turn, gives a section g-^-o-inch thick. He will, however, be not far fi'om wrong by following this rule : reject all sections which do not float, and of the latter preserve as valuable only those which appear as a mere film on the surface of the fluid, requiring to be looked at sideways to be distinctly seen. It is at this stage of the proceeding, that of section-cutting, that we can best judge of the merits of the imbedding mass, which, if found 112 MINUTE EXAMINATION OF THE BRAIN. unnecessarily resistant to the blade, should be modified by the addition of more of the diluting adjuncts, viz., lard, oil, or cacao-butter. The Section Blade. — This is an item of supreme im- portance to the histologist, and it is by no means true, as we often find asserted, that any razor blade answers the pm^pose equally well with the specially prepared knives. I have found this statement made frequently by those who were by no means fortunate in the thinness and delicacy of their sections ; whilst all with whom I am acquainted, who can rejoice in the good qualities of their sections, have always paid great attention to the section-blade which they employ. The qualities of a good blade for section-cutting upon the microtome depend upon its make, form, edge, and tempering. It shoidd be sufficiently long to ensure a free sweep over the whole surface of the section-plate from heel to point, wide enough from back to edge to support and float up the largest-sized section which might have to be cut ; it should be hollowed out on both sm-faces, but be most concave on the sui'face uppermost in section-cutting ; the edge should be extremely sharp, and perfect, whilst the angle formed by the converging sto-faces here should not be so acute as to involve bending of the blade when subjected to slight pressure ; the quality and tempering of the steel should be of the best character. The above points are all most essential require- ments in a good section-blade ; but another important con- sideration is that the plane of the back and edge of the knife should exactly coincide when it rests upon a perfectly level surface as the microtome section-plate — not the slightest degree of tilting being admissible. For the smaller microtomes I have invariably used razor- blades, my three instruments measuring in length and width of cutting- surface as follows : — No. 1 . 4 inches x 1 incli (made by Weeclon) . 4i 1) X 1 ,, ( II Young) 5 )> X U M ( j» Yonng) PREPARATION OF HARDENED BRAIN. 113 The first is a most valuable knife. It is fitted into a short, firm, and fixed handle. The latter, which is my favourite blade, has a folding handle, and is sketched in outline with a section of its concave surfaces in an early number of Brain} Some of the earliest and most discouraging failures upon the part of the tyro in section- cutting depend upon the condition of the blade, and it is necessary that he should be fully impressed with the fact that not only must he secui"e a couple of section-knives with the above qualities, but that he should jealously keep them in most perfect order. To ensure the latter condition, let him observe the following precau- tions : — Use no undue pressm^e against the section-plate whilst cut- ting, and keep the surface of the blade absolutely level with the plate. Pass it frequently along the strop whilst cutting sections. After each day's work examine its edge most critically, and if the slightest irregularity or notching be apparent, it must be reset before use. Keep the blade dry and well polished by a soft handker- chief, and if in a closed handle, have a chamois-leather case made for it. - Subsequent Treatment of Sections. — The sections have now to be removed carefully by a camel-hair brush to methylated spirit contained in the small porcelain capsule, in which they may be allowed to soak for some time to remove all traces of chrome, which otherwise interferes with the subsequent staining they have to undergo. Large Sections through Hemisphere. — The above account refers especially to the smaller class of sections. When it is requisite to obtain sections upon a much larger scale, such as those thi'ough the hemisphere or the whole brain, the process requires modification. The method of imbedding is precisely similar in all its details, but when we come to ^ V'nh- Brain, part iii. p. 3r>3. October, 1878. 114 MINUTE EXAMINATION OF THE BRAIN. cutting the section, special forms of knife are found requisite. The blade which I use measures 16 inches long by 2 inches wide, and is fixed in upright handles at each end. The zinc basin in which the large microtome rests is filled with water, and then sections are cut with a saw-like movement of the blade, and not, as in the former cases, by one complete sweep through the structures. It requires a steady hand and much manipulative skill to obtain these larger sections both thin and perfect, and the student will only perfect himself by frequent and persevering efforts. These large sections can be readily removed by means of sheets of paper upon Avhich they are floated, and this support may be given to them throughout the various subsequent stages of preparation. When the desired number of sections have been obtained, the imbedded plug may be removed, the remaining portion of tissue placed in a 0*5 per cent, solution of bichromate of potash, until required. The microtome should be carefully dried and placed away in a drawer for safety, as the slightest scratching of the polished section-plate will ruin a good blade in a few minutes. Apparati;s for Hardening Tissues and Section-cutting. Winchester bottles for hardening reagents. Jars and 4-oz. phials for hardening tissues. An ice safe. Microtome for imbedding. Microtome for freezing. Griass " preparation- j ar " for receiving sections. Imbedding mass. Spirit lamp. Porcelain capsule. Griass beaker for methylated spirit. Ether spray apparatus. Section-knife. PREPARATION OF HARDENED BRAIN. 115 § STAINING AND MOUNTING SECTIONS OF HARDENED BRAIN AND CORD. The staining reagents advocated by different authorities for sections of the nervous system prepared by hardening are numerous, and the list has become so lengthened since the earlier labours of Lockhart Clarke, Van-der-Kolk, and others, that one great difficulty presented to the student is to make a judicious selection of such as will yield him the best results in the special direction pursued by his work. Amongst those more generally used are carmine and its combinations, picro-carmine, indigo-carmine, and borax- carmine ; the aniline series, comprising aniline blue-black, auiline blue, methyl-aniline, rosanilin or magenta ; hoematoxylin or log- wood ; eosin ; picric acid ; osmic acid ; double chloride of gold and potassium. Many years' experience has convinced me that a large proportion of these reagents may be safely dis- pensed with. The following really comprises all essential staining solutions for nervous tissues : — Haematoxylin. Carmine in ammoniacal solution. Picro-carmine. Aniline blue-black. Aniline blue. Osmic acid. The only solution comprising a double pigment in this list is the picro-carmine, but double staining may be exten- sively employed by the combined agency of the above and two other dyes, the more useful being as follows : — List of Pigments for Dourle Staixtxo. Aniline picro-carminate. Picro-anilin. Osmium with picro-cannine. Hoematoxylin with anilin. Hsematoxylin with eosin. Picro-carmine witli iodine green. I 2 116 MINUTE EXAMINATION OF THE BRAIN. In making clioice of metallic impregnation and reduction by osmium or gold, or of staining by the mineral or vegetable pigments in the list given, the student must be influenced by several considerations. Does he require a uniform staining by a simple dye, or does he wish for differentiation of elements by the use of double pigments — the process of double staining ? Does he wish to examine more specially the cortex or medulla of the cerebrum, or the cortex of the cerebellum, or again, the pons, medulla oblongata, or spinal cord ? Does he desii-e to display certain particular constituents of the cortex — e.g.^ the nerve-cells and their processes — to the fullest possible extent, even at the sacrifice of other structures, such as is often required in minute investigations into the histological constitution of tissues ? Whatever be his object, these questions must receive an answer before the staining reagent can be selected which will yield him the effect desired. I propose to give here the com- position of each reagent, the methods of staining, the special value of each dye for the various histological elements, and to supplement these observations by an analysis of their relative merit for different regions of the cerebro-spinal system. HiEMATOXYLIN STAINING. 1. The Dye. — This reagent has often fallen into great disrepute, owing to the notable variability in the quality of the solutions issued by different makers. The student is strongly recommended to make his own solution, adopting the formula given by Minot or that employed by Kleinen- berg. For the brain and spinal cord I use the former, as preferable to that of Kleinenberg, and I find it at all times most trustworthy in its reaction, and in the uniformity' of results obtained. prepakatio^ of hardened brain. 117 Minot's Formula. Hsematoxylin (crystals) ... ... 3"5 parts. Absolute alcohol ... ... ... 100"0 ,, Alum ... ... ... ... ... I'O ,, Water 300-0 „ First dissolve the htematoxylin in the alcohol, and add to it the alum, previously dissolved in the water. Keep in a closely-stoppered glass bottle labelled " hsematoxylin dye (Minot)." For use, a solution of alimi (0*5 per cent.) is poured into a watch-glass or porcelain capsule, according to the size and number of sections to be stained. A little of the dye is then dropped in, until the solution assumes a light violet tint, when it should be carefully filtered before the sections are immersed. The degree of dilution will soon be learnt after a little practice. Kleinenberg's Formula. a. Make a satm-ated solution of crystallized calcium chloride in alcohol (70 per cent.), and add alum to saturation. h. Make a satm-ated solution of alum in alcohol (70 per cent.), and add Solution 1 to Solution 2 in the proportion of 1 to 8. c. To the resultant mixture now add a fetv drops of a barely alkaline saturated solution of hsematoxylin. Excellent as this logwood solution is for embryonic tissues, I cannot recommend it for the sections of hardened brain, such as we are now engaged with, to the same extent that I can Minot's solution. 2. The Staining Process.— Withdi'aw the sections to be stained from the methylated spirits in Avhich they float by means of a glass rod or camel-hair pencil, and immerse them in the logwood dye contained in a watch-glass or porce- lain capsule. The sections should be lightly stained, other- wise they are spoilt by too diffuse a ooloming and by 118 MINUTE EXAMINATION OF THE BRAIN. acquiring a brittleness unfavourable to subsequent manipula- tion. In his first attempts the student should examine a section occasionally on the stage of the microscope, and so learn to judge of the progress made by the staining. When sufficiently stained, the dye should be poured off, the sec- tions floated up in a porcelain capside half full of water, the capside slightly inclined towards a gentle stream of water from a tap which, falling upon the edge of the vessel, keeps up a constant change of fluid and ensiu'es a most thorough washing of the sections in the currents it produces. Care must be taken that the delicate sections are not torn by this means, which is really necessary to ensure removal of the deposit which adheres to their surface. Next remove the sections to a capside containing methylated spirit, and in one or two hours all tendency to diffuse staining will have disaj^peared. They are now placed for five or ten minutes in rectified spirits or absolute alcohol for dehydration, transferred to the centre of a glass slide, floated up by a drop or two of oil of cloves, which, when it has permeated the tissue and rendered it perfectly transparent, is drained off, and the section mounted in Canada balsam. To ensui'e successful staining with this reagent, the follow- ing points must be carefully attended to : — Stain only the very finest sections, Ijet the sections be perfectly freed by spirit from any acidity (chromic or picric acid, etc.), otherwise the staining will be a failure. Make your own solution of hcematoxylin. Employ Minot's solution in preference to others, and reserve Kleinenberg's for embryonic brain. Never omit the proper dilution and filtering prior to use. Guard against diffuse staining and brittleness from too prolonged action of the dye. Wash the sections very tJiovoiigJiIy subsequent to staining. Remove any accidental diffuse coloration by long im- mersion in spirit. PllEPAKATlON OF HARDENED BKAIN. 119 Dehydrate perfectly before clearing up with, clove oil. Mount in a benzole solution of balsam. 3. Notes on the Reaction of the Dye. — Hsema- toxylin is specially well suited for the display of the various nuclei met with in brain and spinal cord, — e.g., the con- nective nuclei of neuroglia, the peri-cellular and peri- vascular nuclei, the nuclei and nucleoli of the nerve-cells. The larger nerve-cells of the cortex are beautifidly shown in successful preparations, and their primary and secondary branches may be followed for some distance, but never to the extent seen in aniline staining. On the other hand, both neuroglia basis and nerve-structm-es undergo much shrinking by the use of the dye, and from this cause the smaller cells of the upper layers lose, to a great extent, their normal features. The protoplasmic extensions and nerve-fibre net- work of the cortex are indeed very poorly exhibited in logwood, as compared with aniline preparations. The axial cylinders of medullated fibres exposed in transverse section are well exhibited by logwood, and hence the sections of spinal cord and medulla, stained by the dye, show to advantage. Carmine Staining. 1. The Dye. — The most useful solution for hardened brain sections is that recommended by Beale, diluted to the required strength, the original solution being too strong for our piu-pose. Beale's Formula. Carmine (in small fragments) 10 grains. Strong solution of ammonia 1 drachm Price's glycerine 2 ounces. Alcohol h „ Distilled water 2 „ Agitate the carmine with the liquor ammonige in a test tube gently heated over a spirit lamp. When solution is complete, 120 MINLTE EXAMINATION OF THE BRAIN. carefully boil for a few minutes and expose tlie open test tube for an hour to allow excess of ammonia to escape. Add the water, filter, and after the addition of the spirit and glycerine, expose to the air until the odour of ammonia given off from it is very faint. Keep the clear fluid in a stoppered bottle, and whenever carmine becomes precipitated, add a drop or two of liquor ammonitB. Formula for Borax Carmine. Carmine ... ... ... ... 1 part. Borax ... ... ... ... ... 4 ,, Water ... ... ... ... ... 56 „ Alcohol q.s. Dissolve the borax in the water, and add the carmine. Filter the solution, and add just sufficient alcohol to ensure free permeation of the tissue by the dye. Thiersch's Formula. Solution A. Carmine ... ... 1 part. Liquor ammonifc ... 1 ,, Distilled water ... ... 3 , , Dissolve and filter. Solution B. Oxalic acid. ... ... 1 part. Distilled water ... ... 22 „ Mix one part of Solution A with eight parts of Solution B, and add twelve parts of absolute alcohol. Modifications of Grerlach's original carmine dye have also been introduced by Frey and others, but the three above given are all that are really requisite for staining nervous tissues. 2. The Staining Process. — Give the preference to Beale's solution, although its density from the glycerine renders the action slow. Dilute the strong solution with seven times its bulk of water and filter. The sections should be placed in a comparatively Jorge quantity of the dilute PREPAHATIOISI OF HARDENED BRAIN. 121 solution covered from dust and left to undergo very gradual staining, a process wliicli may occupy eight hours, or even longer. "When a section removed to the microscope stage shows sufficient staining, the reagent may be poured off, sujjerfluous carmine removed by gentle washing, and all the sections immersed in a dilute solution of glacial acetic acid (0"5 per cent.) for fifteen to twenty minutes. The acid deprives the specimen of all diffuse staining, and fixes the dye more especially in the germinal centres, whilst at the same time the tint is brightened by its agency. Great care should be taken that neither section nor staining solution is very alkaline in reaction, otherwise the staining will prove too deep and diffuse, and the structure itself injuriously affected. A minimum amount of ammonia, however, must be present in the dye just recognizable by its odour, and if this be not the case, a drop or two of the liquor ammonite should be added to Beale's strong dye prior to making the dilute solution. These sections may now be washed and mounted in glycerine or Farrant's solution, or they may be dehydrated in the usual way by spirit, cleared up in oil of cloves, and mounted in Canada balsam or dammar. With a few of these carmine-stained sections the student shoidd try the following modified process of mounting, whereby valuable information may be obtained. Several years ago I described a method of displaying a great wealth of stmctiu'e on the cortex cerebri by altering the refractive indices of the structm-al elements, and so producing very remarkable differentiation of structui'e.^ I there stated what follows : — " On placing an unstained section of cerebrimi or cerebellum satiu*ated with spirit in the field of the micro- scope, little or no structure is apparent, but if a drop of essential oil be now allowed to run over it, there will be observed at a certain stage of clearing up, and whilst the spirit is evaporating, a sudden starting out in bold relief of the cells, nerve-fibres, blood-vessels, etc., which again disappear or partially fade on perfect clearing of the section. Now, this ' Quarterly Journal of Micros. Sac. vol. xvi. 122 MINUTE EXAMINATION OF THE BRAIN. appearance may be fixed by suddenly dropping over its sm-face a little balsam and permanently mounting. Upon this fact depends the process now to be described. Sections treated with Beale's carmine solution (1 to 7) and washed with the acid, are placed, saturated with spii'it, upon a slide. When the spirit has nearly all evaporated, a drop of oil of anise is allowed to flow over the section (not to float it up), and the clearing is watched on the stage of the microscope ; then, just when the appearance referred to above is presented to view, a drop of balsam is allowed to run over the section, and a covering glass permanently fixed on. In lieu of oil of anise, I frequently employed glycerine with the same results, mounting the specimen in glycerine jelly. * * * I ^vill state my belief that this method will yet prove of most essential service in the estimation of the relative proportion of cell-processes in any individual section, and the most accurate tracing of any existing connections, for not by the deepest aniline staining have I yet succeeded in demonstrating the existence of so thick and numerous a series of j)rocesses diverging from the pyramidal layers of the cerebral cortex as by the method described above." It is satisfactory to find these opinions confirmed by Prof. Stirling in his recent text- book of " Practical Histology." Dr. Stirling says : — " The processes of the cells (of the cerebrum) are best seen in pre- parations which are only iMrtialhj cleared up imder the influence of clove oil. This is a most important method of investigation. I have often seen in this way delicate fibrils, not unlike elastic fibres, and which are not distinct when the section is completely cleared up."^ 3. Notes on the Reaction of the Dye. — Carmine is especially suited as a dye for the large nerve-cells, their contents, nuclei, and nucleoli. It exhibits well the connective cells and the vascular apparatus. For the large ganglionic cells and their immediate environment, nothing can perhaps sm-pass a successful carmine preparation, whilst it does not » "Text-book of Practical Histology," p. 101. Smith, Elder, & Co. PKEPARATIOX OF HARDENED BRAIN. 123 appear to produce any further slirinldng of protoplasm or connective such as is produced by hsematoxylin. It is less adapted for displaying the cell-processes, and wholly fails to exhibit the details of structure in smaller nerve-cells, such as those of the upper cortical layers. It has been regarded, even by so eminent an authority as Charcot, as the only reliable dye for exhibiting the morbid state regarded as sclerosis of the different columns of the cord. This, how- ever, is not the case, since aniline blue-black poi'traj's the lesion even more distinctly. The more important objections attached to this dye are the variable results given ; the little definition often afforded of the tissue elements from the tendency to diffuse staining ; the unpleasant glare of the ca]*mine tint for continuous work, and its unsuitability for examination by artificial light. Picro-Carmine Staining. 1 . The Dye. — This valuable reagent, introduced by Hanvier, is of very special use in the preparation of nervous tissues. It is readily made as follows : — Ranvier's Formula, Best carmine ... ... ... 1 gramme. Water ... ... 10 c.c. Liquor ammonise ... ... ... 3 c.c. liub the carmine up with water, add the solution of ammonia to the fluid in a test tube, and aid the solution of the carmine by gentle heat carefully a2:)plied. When dis- solved and the solution perfectly cold, pour it into 200 c.c. of a saturated aqueous solution of picric acid. Place the solution in an open vessel and Tvith gentle warmth evajiorate to ono-third of its bulk. Filter and keep in a stoppered bottle labelled " Ranvier's picro-carminate dye." Picro- carmine may be purchased in a solid form as a granular and imperfectly crystalline substance — a 1 per 124 MINUTE EXAMINATION OF THE BRAIN. cent., solution is then used. From personal experience I cannot commend its use, and I would strongly recommend the preparation after the formula above given. 2. The Staining Process. — Immerse the sections in a small quantity of the picro-carminate solution for a period of from twenty to thirty minutes. Pour off the dye, draining away all the superfluous fluid, and then, without urishing the sectiom, float them up by glycerine in which they must be mounted. It will often be found advisable to stain each section upon the slide, dropping over sufficient of the reagent to cover it — to clear it up with glycerine and mount it permanently upon the same slide. Picric acid, being soluble in water, is readily removed upon washing these sections ; hence, to preserve the colour due to both pigments, we must carefully avoid washing with water.^ Upon the other hand, washing freely, dehydrating with spirit, and mounting in the usual way in balsam, will yield us excellent carmine preparations, and so far as my experience goes, better specimens than those subjected to the action of the simple ammoniacal or borax solutions. 3. Notes on the Reaction of the Dye. — Picro- carmiiie has the special merit of showing less tendency to diffuse staining than simple carmine dyes. The presence of the two pigments appear notably to restrict their action to the germinal centres, for which they each have affinity. Elastic tissue and muscle will be stained yellow, whilst nuclei and connective take the carmine tint. Minute nervous plexuses are poorly shown, as they occur in the structure of the cortex ; hence, the nerve-cell processes and their ramifi- cations can rarely be followed to any distance. The structure of the investing membranes and the vascular apparatus is better defined by this reagent than any other we are acquainted with. In fact, the merits and demerits of carmine staining, pertain to the picro-carminate, although, for powers of 1 This difficulty is also overcome by washing in a saturated aqueous solu- tion of picric acid, and dehydrating in an alcoholic solution of the same acid. PREPARATION OF HARDENED BRAIN. 125 differentiation, it is superior to simple amraoniacal carmine, and its roJe as a staining- reagent more extensive. For com- bination with other dyes, such as aniline, logwood, and osmic acid, it is peculiarly useful. As a general dye for nerve- structures, it ranks next to aniline and aniline picro-carminate, and is far superior to logwood. Aniline Staining. 1. The Blue-black Dye.— This, which is by far the most valuable of the aniline series of dyes for the brain and spinal cord, is thus made : — Aniline blue-black 1 gramme. Distilled water 400 c.c. Dissolve, filter, and keep in a stoppered bottle, labelled " anihne black dye, aqueous solution, 0-25 per cent." It may, however, be convenient to keep a stock solution of 1 per cent, strength, as rapid staining is occasionally required, and to dilute, as required, to 0-2-3 or O'o per cent., always filtering these dilutions prior to use. The solution, as above given, may be employed for staining fresh and hardened sections, the aqueous solution being the best dye we possess for the former. The alcoholic solution, as first recommended by Mr. Sankey, was the following : — Aniline blue-black ... 5 centigrammes. Water ... ... ... 2 cubic centimeters. Dissolve and pom- into it 99 c.c. of methylated spirit. Filter the solution, and label "alcoholic solution of aniline black, O'Oo per cent." Professor Stirling advises the use of a solution double the strength of the above, thus : — Aniline blue-black ... 1 decigramme. Water ... ... ... 4 cubic centimeters. Dissolve, and add 100 c.c. of rectified spirit, and filter. Label, " anihne blue black, alcoholic solution, O'l per cent." I much prefer the aqueous solution for most pm-poses. 126 MINUTE EXAMINATION OF TflE BRAIN. 2. The Staining Process. — Sections of liardened cortex, pons, medulla, and spinal cord, may alike be left in the aqueous solution (0*25 per cent.) for one hour. In this time they will, generally, be found stained to a sufficient extent, when they must be removed to a vessel containing water, and well washed from superfluous dye. Next, dehydrate by rectified spirit or absolute alcohol ; clear up by oil of cloves, and mount in balsam or dammar. Sections of Cerebellar Cortex shoidd be deeply stained by aniline, gently washed in water, and immersed for twenty to thirty minutes in a solution of chloral hydrate (2 per cent.). Next transfer them to the following solu- tion : — Solution of chloral (2 per cent.). Oil of cloves equal parts. Alcohol ... ... ... q. s. to dissolve per- fectly, and form a clear solution. Add the alcohol by degrees, stirring the solution with a glass rod, and avoiding excess of spirit. During use, carefully cover the watch- glass containing this solution, so as to avoid evaporation. The chloral removes diffuse staining, whilst the clove oil clears up the section, and enables us, by examining one occasionally under a low magnifying power, to decide when they have reached a satisfactory stage. When this has been attained, remove your section to a slide ; rapidly wash with a little pm-e alcohol ; thoroughly clear with clove oil, and mount with balsam. The alcoholic solution of aniline also stains sections of cerebrum, pons, and medulla, and must be cleared and mounted in the usual Avaj^ Grlj^cerine being a powerful solvent of aniline, must not be made the medium for mounting these sections. 3. Notes on the Reaction of the Dye. — Its action is energetic, and its results are certain and constant. It is readily controlled, so that any depth of staining may be obtained with ease. The tint given varies from a bluisli-grey to PREPARATION OF HARDENED 15RAIN. 127 a deep bkie-'black, and is a pleasant one for the eye, causing little or no fatigue. It enables us to obtain the clearest and sharpest definition of elements in a tissue, without modifying their structm-e by shrinking or other change. No otlier staining reagent displays the nerve-cell processes to sucli a remarkable extent as does this dye, the very finest ramifica- tion being followed out with ease. It has a special affinity for protoplasm, staining the nuclei of the nerve-cells most deeply, then the nerve-cells themselves and their protoplasmic extensions, and, to a less intense degree, the nuclei of the neuroglia and perivascular walls. The finely-formed nerve and connective mesh-work, forming the basis substance of the cortex, is stained of a pale grey. This dye fails to produce any action upon the medullated sheath of nerve- fibres, affecting only the axis-cylinder. Transverse sections, therefore, of nerve-fibres, such as are seen in cross sections of the medulla, cord, and nerve-trunks, exhibit the axis-cylinder stained of a bluish-black tint, the unstained white matter of Schwann siuTOunding it ; whilst the intertubular connective, lightly stained, differentiates the medullated tubes from each other. The value of this clj^e for connective tissue is very limited, its role being chiefly confined to the nerve-elements. OsMic Acid Staining. This method we owe to Professor Exner. It is peculiar in the fact that the hardening and staining proceed simultaneously, the same reagent being employed for both purposes. The preparation of the hardened brain hy im- mersion in osmic acid has ah-eady been alluded to, and we have now simply to detail his further treatment of the sections so obtained by the microtomo. The sections, owing to the deep staining they undergo, must be extremely thJn and should be placed in glycerine immediately, since pro- longed immersion in alcohol injm-es them seriously. Transfer a section to a glass slide and add a few drops of strong liquor ammonia?. Absorb all superfluous moistiu'e around the section 128 MINUTE EXAMINATION OF THE BRAIN, with blotting jiaper, and after waiting a short time for the ammonia to effect the section thoroughly, place the cover glass on without injury to the preparation which has heen softened by the reagent, and examine immediately on the microscope stage. It is at this early period that the section shows to greatest advantage. For permanent preservation Exner surrounds the cover glass with the soluble silicate called water glass. Formerly an ammoniacal carmine solu- tion was used, but Exner found that the results obtained could be attributed only to the reaction of ammonia, and so he has dispensed with any carmine staining as the osmium suffices for all pui-poses. Notes on the Value of this Method. — The meduUated fibres can be traced upwards into the highest realms of the cortex, exhibiting a wealth of structure which no other method displays. The meduUated sheath is deeply stained and can be traced distinctly in the case of the smallest nerve- fibres. The nerve-cells, although stained, do not form such prominent objects as by other methods of staining ; this process being especially adapted for tracing the ultimate course of meduUated fibres through the difPerent layers of the cortex and determining their final destination. Exner states that the staining of the minute fibres occasionally disappears in time, and the student should also be aware that the brain- structm'e swells up so much under the agency of ammonia that the section is increased by one-third its full diameter.^ On the Use of Compound Pigments. Under this head I would include some of the most valu- able methods we possess for delineating the minute structures of the nervous system. Picro-carmine, as consisting of two pigments, would naturally fall under this category, but since it is employed in the same way as the simple dyes, I have ^ For results obtained by Prof. Exner with this method, sec Original Memoir (op. cit.), or abstract of the same in Brain, part xv. PREPARATION OP HARDENED BRAIN. 129 found it more convenient to include it amongst them. The methods of staining to which I now refer are those in which the tissue is first submitted to one dye, and the result subse- quently modified by the addition of a second pigment. In these cases, either different histological elements assume the tint of each pigment, or the former staining is greatly improved in character by the second pigment combining and modifying the tint acquired. In the former case only does a genuine double staining occur ; in tlie latter we obtain a single tint, but one of valuable quality. 1. Aniline Picro-carminate Staining. — Three pig- ments are here used, viz., the aqueous solution of aniline blue-black (0"25 per cent.), and Eanvier's compound dye, picro-carmine. Sections, which should be very thin, may be stained on a glass slide, by dropping over them from a pipette sufficient picro-carmine to cover the section completely. When deeply stained by this reagent the latter is di'ained off and the section covered in a like manner by a quantity of the aniline blue-black solution. It will be found that the action of the aniline proceeds much more rapidly upon a section stained by picro-carmine — ten minutes usually sufficing to produce the desired effect. This result is acquired when upon draining off the dye the section is found to have changed from the bright carmine to a deep violet tint. Wash the sections well in water, dehydrate by spirit, clear by clove oil, and mount in balsam. In this way the most beautiful effects are obtained, which are specially valuable and instruc- tive. The tint is much less fatiguing to the eye than the bright glare of carmine, whilst in the differentiation of nervous tissue in the hardened brain this method of stain- ing appears to me unrivalled. The deeper the tint desired the longer immersion in aniline must be practised, but for the more satisfactory and pleasing effects I have usuallj^ found it suffice to stain for half an hour in picro-carmine and fifteen minutes in aniline. Notes on the Reaction of the Dye. — This compound K 130 MINUTE EXAMINATION OF THE BRAIN. staining enliances tlie value of an ordinary picro-carminate preparation in the fact that a better differentiation of structure is obtained, and examination by artificial light rendered as agreeable and valuable as by day-light. With all the advantages of a picro-carmine staining we have conjoined tlie sjiecial action exhibited by aniline for the cell-processes and finer nervous meshwork, whilst at the same time the general tint is deeper than by picro-carmine, and the contrast betwixt the deeper and lighter stained parts more marked. The nem'oglia is stained faintly; the connective nuclei are prominent objects; the nerve-cells are well shown, the nucleus taking a much deeper tint. The axis-cylinder, in transverse sections of medullated fasciculi, is stained of a deep purple, the intertubular connective and its nuclei being of much lighter hue. The vascular channels and their nuclear elements, which are not satisfactorily shown in simple aniline staining, are exhibited to great advantage. I find this method of staining very suitable for displaying the coarse structure of the brain, and sections through a whole hemisphere treated by this method are most instructive for naked-eye examina- tion or by low-power objectives. 2. Picro-Aniline Staining. — A useful staining of medulla and spinal cord may be obtained by emplojdng Judson's " Cambridge blue " as the first pigment, washing oif superfluous dye, and then by momentary immersion in a saturated solution of picric acid the section acquires a bril- liant green, which exhibits structural details remarkably well. Since both pigments are soluble in alcohol, the sections should be very rapidly dehydrated, cleared by clove oil, and mounted in the usual manner. 3. Osmic Acid and Picro-carmine. — The section is immersed in a solution of osmic acid (1 per cent.) carefully covered over so as to confine this very volatile reagent as far as possible to the tissues to be acted upon. "When the latter has acquired a dark-brown tint the section should be removed, well washed, and lightly stained with picro-carmine. PREPARATION Ol' HARDENED BRAIN. 131 Such sections should be mounted in glycerine or glycerine jelly. Sections through the hemispheres of the brain in small animals, or the pons and medulla may be conveniently treated by the osmic acid contained in a watch-glass covered by a small glass plate. The above is a most valuable method of staining. 4. Haematoxylin with Aniline. — This, like the last, gives a genuine double staining. Sections are first stained by logwood according to the directions already given, and immersed for a fcic seconds only in the aqueous solution of aniline blue-black (O'o per cent). A solution of chloral hydrate (2 per cent.) will remove any excess of aniline staining. Wash the sections well, rapidly dehydrate by alcohol, and mount sec. art. This process is chiefly adapted for sections of cerebellmn, and its special value will be referred to later on. The above are all the methods of staining I have found to be of greatest value, but I append here two methods of double staining for the cortex of the cerebellum, advocated by Professor Stirling,^ of the merits of which I have not had personal experience. 5. Eosin and Logwood. — Stain a section for a few seconds in a very dilute watery solution of eosin (1 part to 1,500 of water) until it has a faint red colour, Grreat care must be taken not to over-stain. Wash with water, stain the section with logwood, and mount in dammar. 6. Picro-carmine and Iodine Green. — Stain a section in picro-carmine. Wash it in water acidulated with dilute acetic acid, and, after washing in pure water, stain again by means of iodine green, and mount in dammar. § STAINING OF SPECIAL REGIONS OF THE BRAIN AND SPINAL CORD. The Cortex Cerebri. — The cortex at the vertex in the frontal regions should by preference be stained by the ' "Practif-al Histolog'y," p. 100. k2 132 MINUTE EXAMINATION OF THE BRAIN. aqueous solution of aniline blue-black which has so remark- able an affinity for the nervous protoplasmic masses and their extensions, and which in these regions are so numerous. Next in value to aniline are the pioro-carminate and logwood dyes. With care very beautifid sections may be obtained from this part of the brain stained with picro-aniline, but a good aniline blue-black surpasses all others in intrinsic merits and for purely anatomical details. When it is desired to examine critically the contents of the nerve-cells with regard to morbid change the picro-carminate gives equally good results with the aniline. No reagent, on the other hand, exhibits so remarkably the proliferation of Deiter's corpuscles in the cortex as does aniline. In more posterior planes, and especially at the occipital pole of the hemisphere, where layers of the granule-cell formation predominate, the hematoxylin dye brings out the distinctive features of these realms better than any other. The nuclei of the crowded granide series are deeply stained by this reagent, although the large nerve-cells in the inter- mediate layers are but faintly seen. It is on this account advisable to attempt double staining by logwood and aniline when both granule cells and the larger nerve-cells are well shoAvn. The same remarks apply to the cortex in the olfactory region, where, in like manner, small granule elements predominate. The peculiar crowded cell-formation of the cornu ammonis stained by aniline blue-black affords beautiful preparations. The Cortex Cerebelli. — The granule layer of the cerebellar cortex is readily stained by any of the pigments more generally used, but not so the layers of Pm-kinje or their cell-processes, which branch out so abundantly in the pure grey layer. Picro-carmine and logwood alike yield fine, yet imperfect, preparations, since the mere outline of the Pm-kinje cell or its nucleus is often all that is visible in this layer. Occa- sionally, however, a few branches may be seen. To exhibit PREPARATION OF HARDENED BRAIN. 133 the great profusion of branches arising from these cells stain with aniline black, or preferably employ the double staining by logwood and aniline black. In these cases the granule layer will be of a bright purplish blue, whilst the cells of Purkinje will be distinctly mapped out, the nucleus of a bluish black tint, and their branches displaying a perfect forest of twigs. The Central Medulla. — The student should make sec- tions, both in a vertical and horizontal direction, through the brain of the smaller mammalia, e.g., the cat, dog, or rabbit, and stain these preparations with the double object of utilizing them for coarse examination by the naked eye or two-inch objective, to learn the relationships of the various central structures at different planes, as also for the more arduous duty of tracing out the course taken by the different systems of meduUated fasciculi in the interior of the brain. Such preliminary work he will find invaluable when he attempts to unravel the intricate mechanism of the human brain. For the coarse examination of the larger sections through the whole brain or one hemisphere, the aniline picro-car- minate has always appeared to me the better method of staining, but for the more minute microscopic tracing of central fasciculi the double staining by osmium and picro- carmine is the only reliable method. It must be remembered that whenever we are dealing with sections carried transversely to the axis of the medullated fasciculi these latter will be well delineated by aniline blue- black, picro-carmine, or logwood ; but where the plane of section lies parallel with the long axis of these fasciculi, the more reliable staining is that of the medullated sheath by means of osmic acid. Hence it arises that in following out the lengthened course of fibres through the brain by sections along their planes, osmium is the most valuable adjunct, whilst the structure of the medulla, studied in transverse section, is best treated by other reagents. Although when 134 MINUTE EXAMINATION OF THE BRAIN. dealing witli the more extensive areas, as in sections tlirough the hemispheres, it is advisable to obtain extremely thin j)reparations, yet the vast majority of valuable sections for the purpose of tracing the central medulla are most unsuit- able for minute examination of the cortex, the details of which will be very poorly delineated. The choicest sections through the cortex, such, in fact, as are essential to a favour- able investigation of its structure, must be of extreme tenuity — a degree indeed not attainable in large sections through the hemispheric mass. Let the series of preparations illustrative of the minute structure of the cortex in diiferent realms, therefore, be wholly distinct from those illustrative of the central medidla and basal ganglia, since the methods of preparation which are most suitable for these diverse parts diifer so essentially. On the other hand, Exner's process is available for both regions. The Pons, Medulla, and Spinal Cord. — The same method of staining is applicable to all these parts. Logwood has been used extensively for these regions, carmine still more so ; whilst the anihne reagent, which I regard as of far the greater value, has been comparatively neglected, at least so I judge from the fact that whenever sections of cord or medulla are exhibited, the carmine preparations infinitely outnimiber the aniline. A tolerably thick section of medulla or cord appears wonderfully thin when stained by carmine and cleared up by oil of cloves ; it shows to very fair advantage even to the higher powers of the microscope, and any inequality of surface or scoring from the frayed edge of the section-knife is obscured or entirely concealed from view. This is not the case with the aniline preparations. The depth of tint here not only warns us but too surely of any undue thickness of our section, but shows up any faults in the section due to scoring or tearing of structiu-e to a remarkable and most unpleasant degree. Hence, I incline to the belief that faults really attributable to the section- PKEl'AUATroN OF HARDENED BRAIN. 135 cutter and liis blade' have been credited to the dye, which has, therefore, fallen into comparative disrepute. Of this, however, we may be certain, that sections of medulla and cord properly stained by aniline blue-black are the most beautifvd preparations of these regions we can by our present methods possess ; and that a really good aniline preparation of these parts must of necessity be a reyy thin and perfect section, — a statement which can scarcely be made of carmine preparations. The student should therefore possess himself of the thinnest possible sections of the different regions of the medulla and sjjinal cord, prepared by the aqueous solution of aniline blue-black, and with due care to the con- dition of his section-knife, he may thus prepare a most invaluable series of sections ; yet from the necessary fine- ness of the sections, he will meet with greater difficulty in obtaining perfect preparations than by the carmine staining. Whilst thus giving the foremost place to aniline blue-black for staining these regions, I would not wish to undervalue the merits of picro-carmine. Next to aniline, it is pre- eminently useful here. Do not, however, be deceived by its peculiar power of concealing the demerits of your section, and so be led to regard a section as thin because it appears so when mounted. In this way, minute details may be wholly overlooked which really thin sections would have exhibited. With the high powers the actual thickness of the section may be decided readily. Apparatus required for Staining and Mounting. Bottles of staining reagents Porcelain capsules Watch-glasses Slides Cover-glasses Tray for fresh slides Bottles of mounting media Grlass rods Pipettes Camel-hair brush Funnel and filtering paper Mounted needles Turn-table Bottles of cement CHAPTER X. PREPARATION OF NERVOUS TISSUE IN THE FRESH STATE. Among the facilities offered for immediate examination of brain and spinal coi-d in the recent state, two processes present themselves for examination ; these are — 1. Methods of section-cutting and preparation of frozen tissues. 2. Methods of dissociation and teasing out of fresh tissues. We should perfectly familiarize ourselves with all these methods. There are certain difficulties peculiar to the pre- paration of fresh nervous tissues, and not met with in the manipulation of hardened sections, with which it is well to be acquainted. We shall recognize in the details of pre- paration now to be given, the means adopted for overcoming these obstacles. Sections of frozen brain must be extremely thin for satis- factory preparations, and these most delicate films absorb water so rapidly that the constituents undergo rapid dissocia- tion when floating in water. Again, after removal to a slide, the upper surface is found highly repellant of watery solutions, so that the application of osmic acid equably over its surface is a matter of some difficulty when dealing with so fine a film. Lastly, fine sections of spinal cord exhibit such rapid endosmose of fluid, that unless each section be removed immediately it is floated off the blade into glyce- rine, the nervous elements swell up and burst through the encircling girdle of membranes, becoming completely dis- PREPARATION OF NERVOUS TISSUE IN THE FRESH STATE, 137 sociated. The first difSculty as regards the cortex is met by the osmio acid treatment, the second is overcome by a little i^ractical manipulation, and the difficulty connected with section of the cord is wholly avoided by glycerine diluted with one-half or two-thirds its bulk of water. It must be remembered that all alcoholic and highly astringent reagents must be excluded from our list for staining purposes, and therefore haematoxylin and several other dyes employed for hardened brain are wholly inadmissible for fresh nervous tissues. We are, therefore, chiefly restricted to aniline blue- black, carmine, picro-carmine, and osmic acid. The osmium and aniline are especially valuable agents. § PREPARATION OF SECTIONS FROM FROZEN TISSUES. The Freezing Method. — Use the ether freezing micro- tome and secure it to a firm support, as a table or ledge in front of an open window, where a cool di-aught plays over the section-plate. Place a large deep glass vessel half -filled with clear water on the support in front of the microtome ; have the ether-spray apparatus ready on the left hand, and the section-blade on the right. Throw across the knees a soft towel, with which the under surface of the section-blade has to be gently wiped occasionally to remove superfluous moisture. Next take up the section-blade, and holding it horizontally, pour upon its upper surface a small quantity of ether, allowing it to sweep from end to end, and agitate the blade in water until the blade, on removal, remains perfectly wet from end to end. Repeat the ether wash if the surface still remains somewhat greasy, as in this state it is unsuited for section-cutting. Lower the freezing chamber of the microtome until its surface, or freezing plate, is four or six millimeters below the upper surface of the section-plate. Place upon the upper surface of the freezing chamber the tissue to be frozen, which should be but a little over a quarter J 38 MINUTE EXAMINATION OF THE BRAIN. of an inch thick. Introduce the nozzle of the ether-spray instrument through the opening in the left-hand of the freezing chamber, so that the spray be directed upwards against the freezing plate immediately beneath the tissue. A steady current will, in a few seconds, cause blanching of the tissue next to the plate, to which it now firmly adheres, and fi'eezing proceeds rapidly upwards, as evidenced by its colour and firmness. It is not necessary to freeze above the level of the section-plate. Remove the unfrozen tissue down to a level with the section-plate by a sweep of the blade — plunge the latter into water, lightly wipe its iinckr surface upon the towel, and raising the section by the micrometer- screw, cut the first section with a sweep away from you, and from your left to yom* right hand. The section must be floated off in the glass vessel, and not plunged beneath the sm^face of the water. One should aim at acquii'ing the greatest expedition at this work, rapidly floating off each section, and wiping the blade preparatory to the next. It is all-important that fresh sections be removed from the water in which they float as quickly as possible, whilst, at the same time, a number of sections should be cut before the frozen mass begins to thaw and loosen from the plate. Practised manipulators can with ease cut a dozen fine sections ere the mass loosens from the plate, but the tyro, Avhen simply practising the cutting of sections, is slow in his manipidation, and finds the mass loosens before he has secured three or four specimens. Two or three puffs from the spray, however, will, at this stage, fix it to the plate again, and thus he may with ease cut through the whole depth of tissue with very little expenditm-e of ether. When he has obtained sufficient manipulative skill at section-cutting, he will find it advisable to pass the first half-dozen sections through the second stage of the process before he cuts another series, so as to avoid the injury resulting from prolonged floating in water ; this last statement holds good for all nervous tissues alike. There is, perhaps, no method of obtaining fine sections of tissue so exj)editiously and with PREPARATION OF NER\"OUS TISSUE IN THE FRESH STATE. 139 such extreme simplicity of detail as that just described, and certainlj none involving so little expenditure of time or labour ; yet, as the beginner will always meet with some obstacles in his first attempts, however simple the process, it will be as well to indicate those which most frequently present them- selves. His failiu'ss will invariably be due to one or other of the following causes : — 1. The 1 0)12)6 rature of the room above 60° F. This also involves unnecessary waste of ether. Freezing should only be practised by ether spray when the temperatm'e of the atmosphere falls below 60° F. 2. The brain mass frozen too high. Brain-tissue, when fi'ozen hard, cannot be properly cut ; in fact, our sections are invaiiably obtained from the tissue which is slowly thawing, and which is always of most delicate consistence for cutting. On this account it is not necessary to freeze up to the level of the section-plate. 3. Too much uxiter on the blade. If this superfluous fluid runs off on to the section and freezing-plate, it sets into a solid icy mass, which injm-es the blade and greatly retards section-cutting. 4. Water freezes over the. section-dilate. The uneven sur- face thus produced prevents section-cutting. The difficulty is removed by never neglecting to draw the under surface of the blade over the towel before each section is taken. 5. Brain freezes too Jiard inrspcctive of the above conditions. This only results when the tissue is extremely oedematous from morbid states, and when the temperature of the siu'- rounding atmosphere is so low that freezing is unusually rapid. The difficulty is met by moistening the upper siu'face of the blade with glycerine instead of water, and carefully guarding it from extending to the freezing plate. 6. Sections tear or cling to the blade. This residts from the greasy surface of the blade retaining no water to float up the section. 7. Tissue cannot be frozen to plate or loosens too soon. The 140 MIMUTE EXAMINATION OF THE BRAIN. first occurs when glycerine or other medium which cannot be frozen has been accidentally smeared over the plate — the latter usually from want of rapid manipulation on the part of the operator, or too warm an atmosphere for satisfactory freezing. 8. Lastly, the icell or freezing chamber may he too sni'dl, in which case freezing is not only retarded, but subsequent thawing is hastened. For my own part I would strongly recommend this portion of the instrument to be full 2 inches in diameter by 1| inches deep. We now proceed to the subsequent treatment of our sections. Staining Fresh Sections of Cortex. — In this stage our sections pass through two processes — the osmic acid treat- ment and aniline staining. Take a perfectly clean glass slide, pass it beneath a section floating in water, and, fixing it to the slide by a needle, remove it carefully, draining off all superfluous fluid from the slide. Remove each section in a similar way, and next, by means of a pipette, let two or three drops of osmic acid solution (0"25 per cent.) fall on the slide and float up the section ; with a pen-knife carefully spread this fluid over the upper surface of the section, which, on account of the repulsion afforded, gives a little trouble with extremely thin films. This procedure is, of course, not necessary where the section has been sunk in water, but the more delicate sections float, and can be plunged beneath the surface of the water only at the risk of ruining them. A little practice soon enables us to carry the osmic acid over the most delicate films without tearing them. Sections thus treated should not remain over one minute in the osmic acid of the strength named, but should at once be immersed in a vessel of pure water and left here for five or ten minutes. By this time all superfliious acid has been removed, . and the osmium has " fixed " the nervous structures, so that they are manipulated without danger and do not deteriorate in water. The sections may now be stained collectively, or, as I prefer PREPARATION OF NERVOUS TISSUE IN THE FRESH STATE. 141 it, each section should be placed on a slide, and sufficient aniline blue-black dye (0'25 per cent.) poured on to completely cover the film. Place the slides under cover. It is well to have a small tray with a shelf attached around its sides on which the slides may rest, the tray being fitted with a cover. The staining with the aqueous solution of the dye occupies about one hour ; alcoholic solutions of the dye are of course inadmissible. When staining is complete a pipette will remove superfluous dye, or it may be drained off carefull}'', and the sections again plunged into water and gently moved about imtil well washed from unfixed dye. There are certain circumstances which the student shoidd be aware of in adopt- ing this process of staining, and these I will here briefly allude to. If the osmic acid solution be too strong or left on the section too long, subsequent staining by aniline will prove very unsatisfactory, and, moreover, the osmium staining becomes apparent, and is dissolved out subsequently by the benzole solution of balsam tinting the latter strongly and spoiling the preparation. Since the osmic acid is used simply to give the sections the necessary consistence for manipulation, and not for the purpose of staining, it should be employed in the weakest form consistent with this action, and the sections exposed to its agency for the very shortest period necessary, and very thoroughly washed prior to staining. If the osmic acid be unequally spread over the section, those parts not immersed will stain with less vigour by aniline. Again, when all the above precautions have been taken, it is sometimes found that sections exhibit a rough, irregularly- stained surface, really due to the edge of the section-blade being somewhat frayed, and so tearing the delicate structures in cutting through them. Mounting for Permanent Preparations. — Let each section, when well washed, be received upon the centre of a perfectly clean glass slide ; all fluid drained off, and the specimens again placed upon the shelf of the covered tray, to 142 MINUTE EXAMINATION OF THE «RAIN, dry spontaneously. The process may be hastened, if neces- sary, by enclosing them within a bell-glass along with a capsiile containing strong sulphuric acid. When perfectly dehydrated, let a drop or two of a benzole solution of balsam fall on the section, and adjust the cover- glass. Staining Fresh Sections of Central Medulla. — As before stated, the same method of staining is not alike suitable for both cortex and medulla. The aniline process, just described, is in every way adapted for the cortex of the cerebrum and cerebellum ; but when our object is to follow the com-se of the central medullated fasciculi, and examine the structiu'e of the basal ganglia, the use of osmic acid has to be invoked. Before practising on the more extensive areas of the human cerebrum, it would be well for the student to slice the brain of one of the smaller animals — (the cat, dog, rabbit, are very suitable) — upon the freezing microtome, carrying sections through the hemispheres in vertical and horizontal planes. Such sections should be extremely fine, and on removal on a slide to the stage of the microscope, shoidd exhibit, in an exquisite manner, the details of medullated structures. The grey matter will, of course, be translucent, and apparently structureless ; but the medullated fasciculi will appear in striking relief of a pure white, the minutest fibre readily followed by a comparatively low-power objective. Our object, however, is to render these structures, not only clearly-defined, but permanent preparations, and this may be effected by the following procedure. The finest sections are removed as rapidly as possible from the water in which they float upon a slide, and floated up immediately by osmic acid (1 per cent, solution)^ drawn also carefully over the upper surface of the section. The slide is placed aside, closely covered over, so as to confine the vapom- of this very volatile reagent as much as possible to the section. In a period, varying from five to ten minutes, the sections are floated off into Avater, and freely washed. They acquire rapidly the deep brown tint of osmium, and can be manipu- PREPARATION OF N;ERV0US TISSUE IN THE FRESH STATE. 143 lated without fear of tearing. The depth of tint required can be best learnt by experience. After well washing, the sections may either be mounted as they are, or immersed for a few moments in picro-carmine ; the latter is, perhaps, the best plan to adopt, as the grey matter is thus shown stained, in striking contrast to the medulla. The mounting of these preparations is more tedious, as they require to be j)reserved in glycerine or aqueous solutions, and careful sealing-up is therefore requisite. Take up the sections on the centre of a slide, after washing off the picro- carmine dye, and allow a drop or two of strong glycerine to float up the sections and remain exposed for five or ten minutes. The section becomes clearer and freed from much water by this means, and the glycerine is drained off. Just sufficient strong glycerine is again di'opped on to the section to cover it completely, and the cover is placed on. All traces of superfluous glycerine must be carefully removed from the margins of the cover-glass after it has been gently pressed down, and on no account must any glycerine remain on the slide just outside the cover- glass. A thin coating of the lead cement is laid on around the square or circle of thin glass, just overlapping by a couple of millimeters the edges of the latter. This must be allowed to dry completely, when a second coating is run on, and also allowed to dry. Over this, a layer of gold size may be painted, and a finish afforded by the Avhite zinc paint. This method of sealing-up, although tedious, is most reliable and durable ; it well repays the trouble taken. The same method may be employed where preservative fluids, such as Farrant's, Groadby's, or sodium chloride with camphor solution are - used. We should be cautious in using these fluid preservatives, to lay the gold size above and not beneath the red lead cement. A weak solu- tion of chloride of sodimn, made with camphor- water, also answers well for preserving the preparations stained by osmie acid alone. 144 MINUTE EXAMINATION OF THE BRAIN. § PREPARATION OF NERVOUS TISSUES BY DISSOCIATION. Prior to the systematic section-cutting of frozen brain, various methods of fresh preparation had been tried. Thus, a thin section of cortex was often pressed out between the cover-glass and slide, and its vascular system fairly well displayed ; but the nerve-cells and their delicate ramifications could not, of course, be detected by such a coarse method of procedure. It was found necessary to prepare the section by certain reagents whereby dissociation of elements might be secured, whilst some form of staining reagent was likewise essential. Amongst the earher attempts of this kind, was that made by Grerlach,^ but the process is applicable only to the large ganglionic cells of the spinal cord. I have myself employed a process less tedious than that of Grerlach, having the advantage of being rapid and immediate in application, with results which, to me, appear equivalent to what is obtained by the more lengthened process. I shall describe both. Gerlach's Method of Dissociation. — The finest pos- sible sections are made longitudinally, through the perfectly fresh spinal cord of the calf or ox, and are immediately placed in a very weak solution of bichromate of ammonia (1 part to 5,000 or 10,000 parts of water). Let them remain here for two or three days, at a cool temperature. Next, immerse them for twenty-four hours in a dilute solution of ammoniacal carmine. Wash the sections well with distilled water, and tease out the nerve-cells with a needle, under a lens. Preserve in glycerine, or evaporate to dryness on a slide ; moisten with oil of cloves, and mount in Canada balsam. Dissociation may thus be practised in the case of ganglionic cells, wherever they are found, the macerating fluid being either dilute bichromate of potash or ammonia, Miiller's fluid, ' Strieker's " Human and Comparative Histology." Syd. Soc. Vol. ii. p 345. PREPARATION OF NERVOUS TISSUE IN THE FRESH STATE. 145 or iodized serum, the process of maceration occupying from one to three days. Rapid Dissociation and Teasing. — Make a fine section with a razor through the anterior cornu of the cord in its lumbar enlargement. The section must be made longitudinally, and either by hand or on the freezing microtome. Place the section in the centre of a glass slide ; saturate it by immersion in Miiller's fluid for a few minutes ; place a glass cover over the section, and gradually compress it by a mounted needle between the cover-glass and slide. Before a fine film is obtained, the shde is carefully wiped on its under sm-face, and examined by a low power under the dissecting microscope. Even as opaque objects, the ganglion cells Avill now attract our attention by their little masses of pigment. With the slide still under a low objective, steadily and gradually compress the part where the cells chieflj' con- gregate, and, by a gentle rocking movement of the cover- glass, we may thus spread them out over the field, or aggre- gate towards the clearer areas, whilst any alteration they might suffer from this compression, is sure to be very trivial, owing to the elastic resistance of the neuroglia framework. The cover-glass may now be partly pressed and partly tilted off the film, and the mounted needle used to arrange the cells according to our mind, whilst the other textures around may be carefully removed. A few drops of Beale's strong solution of carmine, or the aqueous solution of aniline blue- black (0'25 per cent.), will very rapidly tint the germinal centres of the required depth of hue, and should then be removed by immersion in water, or by allowing a few drops of water gently to flow over the preparation. The cells are dried in situ, moistened with clove oil, and mounted in balsam. Dissociation and Staining of Ganglion-cells of Cortex. — The two methods just detailed are available only for the cells of the spinal cord. For the ganglion- cells of the human cortex, I devised a method which 14G MINUTE EXAMINATION OF THE 15KA1N. was described in the Monthly Microscopical Journal for 1876, and which affords very satisfactory results. The process may be considered under three stages: 1. Obtaining the fihn ; 2. Staining ; 3. Permanent mounting of the prepa- ration. 1. First Stage: The Film. — Strip the convolution of its membranes, and excise a portion convenient for manipida- tion. Hold it betwixt the thumb and second finger of the left hand, so that the index finger may guide and support the blade. Then, with the razor-blade satiu-ated with methylated spirit, cut section after section vertically to the surface of the cortex, and of the greatest delicacy possible by these means. Very thin sections may thus be obtained with little trouble. Each should be placed on a glass slide, and three or four drops of Miiller's fluid allowed to fall upon them from a pipette. Maceration in this fluid for a few seconds, prevents the film adhering, dming the next procedure, to the cover- glass or slide. The cover is next placed on, and so arranged as to cover the film by only one-half its diameter. Place the point of a mounted needle upon the centre of the cover-glass, and by steady pressure flatten out the section into an almost transparent film. Practice will soon enable the operator to so arrange the cover-glass that the extreme edge of the compressed section still occupies the space covered by the glass circle. Now remove the superfluous reagent by rapid rinsing in water, and place the slide in a flat porcelain bath or tray, containing methylated spirit. In from thirty to forty seconds, the cover can be removed without tearing the film. For this purpose, remove the slide, steady the cover by the pressure of a finger against one part of its edge, and pass the point of a needle under the edge, near the medullated portion of the section, and gradually elevate it. "Wash the films from spirit by allowing a stream of water to flow over them from a large camel-hair brush. 2. Second Stage : Staining. — The aniline blue-black solution (1 per cent.), is the most suitable staining reagent. TREPARATION OF XERVOl'S TISSUE IX THE FRESH STATE. 147 It is dropped upon the film as it lies oil the slide, and when sufficiently stained, the superfluous dye is poured off, and the slide lowered gently into water, the film being washed by agitating the fluid around it with a camel-hair brush. Car- mine and picro-carmine may be also used for staining ; but hithei'to the best results have been obtained with aniline black dye. 3. Third Stage : Permanent Mounting. — The speci- mens lying in the centre of their respective slides are now transferred to a bell-glass, so as to exclude dust, and left to dry spontaneously, or the process of desiccation is hastened by including a capsule containing strong sulphm'ic acid. When perfectly dry, let a drop of chloroform fall on the preparation, and immmediately add the balsam (chloroform or benzole solution), and adjust the cover glass. Examination of Neuroglia. The neuroglia may be well shown in the spinal cord by the methods of dissociation above given. It has been especi- ally studied in the fresh state by Boll, Eanvier, Mierzejewski, and others, and the following methods are worthy of note : — 1. Boll's Method. — Thin sections of the brain-substance were plunged into a solution of osmic acid, O'l per cent., and after twenty-four hovu's immersion, were washed in distilled water and kept in a concentrated solution of potassic acetate. For microscopic examination, .these darkened sections were dissociated or compressed strongly betwixt cover and slide. 2. Ranvier's Method. — Osmic acid (1 part in 300 parts of water) was injected interstitiaUy into the fresh spinal cord. The pai-ts infiltrated by the reagent were afterwards removed by the section-knife, torn up, and teased in distilled water, coloured by picro-cai-mine, and examined in glycerine. Tliis, I may add, is a very excellent and valuable method. L 2 148 MINUTE EXAMINATION OF THE BRAIN. 3. Mierzejewski's Method. — ^A fragment of the white substance of the brain, about one cubic centimeter in bulk, was placed for twelve to twenty-four hours in a solution of osmic acid (1 part in 300 parts of water). By this time the preparation was impregnated by the reagent and its exterior dark and callous. The hardened exterior was then sliced off by the section-knife, when the parts immediately beneath it were found pretty equably affected by the osmium. Minute preparations were then obtained from this region, after the manner of Eanvier, viz., by staining with picro- carmine and examining in glycerine. Mierzejewski employed this method satisfactorily in his studies of the neuroglia of the brain in general paralysis.^ Dissection of MeduUated Strands in the Fresh Brain. — Much valuable information may be gleaned by the student in the examinatian of the brain of the smaller mammalia by dissection beneath a fixed lens or dissecting microscope. The brain should be placed beneath the light concentrated by a bull's-eye condenser. The scalpel, mounted needle, and camel-hair pencil are all the aids he requires. In fact, the needle and brush do nearly all the work, the broken-down tissue and grey matter being washed off by the brush filled -with a solution of chloride of sodium (1 per cent.). It is astonishing to one who has not tried this method how much can thus be done. It is well to begin with the very small brains, such as that of the rat. Remarks upon Dissociation of Nerve-Cells. — The student must not regard the methods of dissociation just given as being merely a rough and ready means of displaying the coarse structure of nervous tissue. Where the microtome is not at hand, or cannot be employed, these methods are very valuable ; but, even when possessed of the permanent sections obtained by the microtome, dissociation should supplement our inquiries. The films thus obtained, as well as those off 1 ' ' Etudes sur les Lesions Cerebrales dans la Paralysie Generale.' ' Archives de Fhysiologie, 1873. PREPARATION OF NERVOUS TISSUE IN THE FRESH STATE, 149 the freezing microtome, afford us miicli information upon histo- chemical examination. The elements may thus be treated by osmic acid, salts of gold, platinum, and silver, and a variety of dyes. For examination of the reactions with chemical reagents, I have found it useful to obtain the faintest tint by aniline, just sufficient, indeed, to bring into view the outline of the cells and their nuclei. For this pur- pose a few drops of very weak aniline dye, left on for a few minutes, and then washed off, may be fixed in the germinal centres by a di-op of extremely dilute hydrochloric acid, which is immediately cleared off by water, and the film left in a satisfactory state for noting the effect of reagents. PAET III LIST OF REAGENTS AND MOUNTING MEDIA LIST OF REAGENTS AND MOUNTING MEDIA. The following list comprises fill the more useful reagents which the student will require in the prosecution of the minute examination of the brain. Those marked with an asterisk (*) are the most important, and cannot be dispensed with. Hardening Reagents. 1.* Chromic acid (stock solution, 1 per cent.). Chromic acid cry st. ... 10 grammes. Water 1,000 c.c. Dissolve. Dilute to O'lo pei- cent, for brain, and 0-25 per cent, for spinal cord. 2.* Bichromate of potassium (stock solution, 4 per cent.) . Bichromate of potassiimi ... 40 grammes. "Water (hot) .;. ... 1,000 c.c. Dissolve. Used in dilutions from 0-25 per cent, upwards. 3. Bichromate of ammoniimi (stock solution, 4 per cent.), made as the potassium solution above. 4.* Mailer's fluid. Bichromate of potassium ... 25 grammes. Sodium sulphate ... ... 10 „ Water ... 1,000 c.c. Dissolve. 5. Picric acid solution. Cold satiu-ated solution in water. 154 LIST OF REAGENTS AND MOUNTING MEDIA. 6.* Osmic acid. A solution of 1 per cent, should be kept in a blue glass closely-stoppered bottle, to be diluted when required imme- diately before use. 7.* Methylated spirit. 8.* Absolute alcohol. Formula of tSi-Eci \.l Holutkjns. 9. llutherford's reagent. Cliromic acid ... ... 1 gramme. Bichromate of potassium ... 2 ,, Water 1,200 c.c. Dissolve. 10. Solutions for Betz's method. {a) Iodized alcohol. Alcohol (70 to 80 per cent.), tinted sherry- brown by tinct. iodi. co. {b) Iodized spirit. Methylated spirit, tinted sherry - brown by tinct. iodi. co. ic) Bichromate solutions. Solutions of potassium bichromate from 0*5 per cent, up to 5 per cent. 11. Solutions for Hamilton's method. (r/) Midler's fluid 3 parts. Methylated spiiit ... ... 1 „ Mix. [h] Solutions (aqueous) of ammonium bichromate, 0"25 per cent, to 2 per cent. 12. Kleinenberg's picric acid solution. Cold saturated aqueous solution of picric acid ... ... ... 800 c.c. Concentrated sulphmic acid ... 6 c.c. Mix, filter, and add to the filtrate, Avater 900 c.c. Ll.ST OF KEAGENTS AND MOUNTING MEJ)IA. 155 Staining Reagents. The following may be regarded as a fairly complete list of the reagents more generally employed ; the f ormnlie for special solutions are also given below : — 1.* Carmine. ' Aniline dyes comprising — 2* Hsematoxylin (crystals). irv* a -t it it ^ -r 1 . / 10.* Aniline blue-black. LiOgwood extract. -. , , , 8.* Picric acid (crystals). ^' ,^ " .,. " , ^ . ^ "^ I -'-■^- Iv-osanihn (magenta). 13. Fuchsine. 14. Metli34-aniline. 15. Iodine green. 16. Judson's dyes, espe- cially *" Cambridge blue." 17. Various combinations 5. Gold chloride. (J. Double chloride of gold and potassium. 7. Silver nitrate (0'5 per cent.). 8. Silver lactate (Alferow's formula) . , " p i i v . * ^ • • ■. 1 i \ of the above. d. Osmic acid (1 per cent.). ' Formula for Special Solutions. 1.* Beale's carmine reagent. Carmine (in small fragments) 10 grains. Liquor ammonife ... • • ■ h drachm. Glycerine (Price's) 2 ounces. Alcohol ... •■• ••• ^ 5J Distilled water ... ••• 2 ,, Heat the carmine with the ammonia in a test-tube carefully, boil for a few minutes, and expose for one hour. Add the water ; filter. Add the spirit and glycerine, and expose until the odour of ammonia is scarcely perceptible. 2. Thiersch's carmine reagent. (a) Cannine ••• ••• ••• 1 \)ia:i. Liquor ammonite ... • • • 1 ?> Distilled water 1 » Dissolve and filter. {h) Oxalic acid 1 P'^i't- Distilled water 22 „ 156 LIST OF REAGENTS AND MOUNTING MEDIA. Mix one part of (a) witli eight parts of (b), and add twelve parts of alcohol. 3. Borax carmine. Carmine ... ... ... 1 part. Borax .., ... ... ... 4 „ AVater 56 „ Alcohol ... ... ... q.s. Dissolve the borax in the water, and add the carmine ; filter, and add to the filtrate two volumes of absolute alcohol. 4.* Ranvier's picro-carmine. (a) Carmine Liquor ammonite . . . Water 1 gramme. 3 c.c. 10 c.c. liub the carmine up with water ; add the ammonia, and dissolve with heat carefully applied, (b) Saturated aqueous solution of picric acid, 200 c.c. Add, when perfectly cold, (a) to (b), and evaporate with gentle warmth to one-third its bulk. Filter, and keep in stoppered bottle. 5.* Minot's hsematoxylin dye. («) Heematoxylin crystals Absolute alcohol Alum Water Dissolve the hsematoxylin in alcohol, and add the alum, dissolved in the water. (b) Alum 1 part. Water ... 200 3-5 parts 100 >> 1 5> 300 )> J> Dissolve. For use, pour a little of (b) into a watch-glass, and add sufficient of (a) to colour it a light violet tint. Filter prior to staining. LIST OF REAGENTS AND MOUNTIXCx MEDIA. 157 6.* Kleinenberg's hoematoxylin dye. (a) Make a saturated solution of crystallized calcium cliloride in alcohol (70 per cent.), and add alum to saturation. (b) Make a saturated solution of alum in alcohol (70 per cent.), and add solution {a) to {h), in the pro- portion of 1 to 8. (c) To this resultant mixture, now add a feiv drops of a harely alkaline saturated solution of hsematoxylin. 7.* Aniline blue-hlack (aqueous solution). Aniline blue-black ... 1 gramme. Distilled water 400 c.c. Dissolve, filter, and label " 0-25 per cent." Or, make a 1 per cent, solution ; dilute and filter when required. 8. Aniline blue-black (alcoholic solution). Aniline blue-black ... 1 decigramme. Water 4 c.c. Dissolve and add recti- fied spiiit ... 100 c.c. Filter, and label " O'l per cent." 9. Aniline blue reagent. Aniline blue J grain. Distilled water 1 ounce. Alcohol 25 drops. 10. Rutherford's rosanilin dye. Rosanilin or magenta (crystals) 1 grain. Absolute alcohol 100 minims. Distilled water 5 ounces. 11. Dyes used in combination. Aniline blue-black (Aq. sol., 0-25 per cent.) + ricro-carmine. 158 LIST OF REAGENTS AND MOUNTING MEDIA. Judson's " Cambridge blue " | + Picric acid. j Osmic acid (1 per cent.) + Picro-carmine. Hsematoxylin ... + Aniline blue-black (0*5 per cent.). Eosin (1 to 1,500) ... + Hsematoxylin. Picro-carmine ... + Iodine green. 12. Alferow's lactate of silver : — Lactate of silver ... ... 1 part. Distilled water 800 „ Concentrated solution of lactic acid ... ... ... A few drops. Note. — " The free acid renders precipitation less easy, and the chloride and albuminate of silver are alone formed." 13. Gerlach's gold and potassium solution.^ Double chloride of gold and potassium ... ... 1 part. Water, feeblv acidulated with hydrochloric acid.. 10,000 ,, Sections acquire a pale lilac colom' in this solution in from ten to twelve hours. Solutions for Macerating and Dissociating Tissues. 1. Iodized serum. Fresh amniotic fluid ... 100 c.c. Tincture of iodine ... ... 1 c.c. Carbolic acid ... ... 2 drops. For small quantities, use the aqueous humour from the eye of sheep or ox. Other useful fluids are — 2. Glycerine and water. ' For staining sections of spinal cord by this method, see Art. " The Spinal Cord," by Gerlach, in Strieker's " Human and Comparative Histoloo-y." LIST OF REAGENTS AND MOUXTIXG MEDIA. 150 3, Chloride of sodium solution (0*75 per cent.). 4, Ammonium and potassium bichromate (1 part to 10,000 of water). 5, Midler's fluid, freely diluted. Mounting Media. 1.* Griycerine (Price's) ; 2.* Glycerine jelly (Rimming- ton's) ; 3.* Canada balsam ; 4.* Dammar varnish ; 5. Far- rant's solution. 3.* Benzole solution of balsam. Canada balsam evaporated in a water-bath to a brittle, resinous consistency, is dissolved in benzole until it is sufficiently fluid to drop slowly from a glass rod. 4.* Dammar fluid. Gum dammar, gum mastic, of each ... ... ... h ounce. Benzole ... ... ... 3 ,, Dissolve the gum in the benzole and filter. 5.* Farrant's solution. Glycerine, saturated solution of arsenious acid, gum- arabic, equal parts of each. Let the mixture stand for several weeks, frequently stirring; and when no more of the gum-arabic is dissolved, filter the solution. Cements. 1.* Mr. Kitton's cement for glycerine mounting. White lead, red lead, litharge in powder, equal paris. Mix well. Keep a stock of the mixture ready ground in a bottle. For use — rub up a little of the powder with turpen- tine, and add sufficient gold size to allow it to work readily with a brush. The first coat should always be perfectly dry before the application of a second. IGO LIST OF REAGENTS AND MOUNTING MEDIA. 2.* Zinc-white cement. Griim dammar. . . ... ... 8 oimces. Zinc oxide ... . . ... 1 ,, Benzole ... ... ... 8 ,, Dissolve the gum in the benzole, add the zinc, and strain through muslin. 3. Marine glue. 4.* Gfold size. 5. Brunswick black. 6.* Balsam or dammar varnish. In addition to the list of reagents above given, the student sliould supply himself with a bottle of clove oil, glacial acetic acid, and solution of chloral hydrate, 2 per cent. I ^^ D E X. Absolute weight of brain, 61 Acid, chromic, 105, 153 osmic, 105 picric, 154 Alferow's sUver lactate, 158 Amnioniiun bichromate, 104, 154 AnUice blue -black, 157 picro-carminate, 129 staining, 125 Apparatus, displacement, 65 specific gravity, 63 for hardening tissues and section- cutting, 114 for staining and mounting, 135 Arachnoid, examination of, 9 Arteries, capacity of, 20 dissection of, 15 nutrient, 24 tunics of, 18 B Base of brain, 8 Beale's carmine fluid, 155 Betz's method of hardening, 103 hardening solutions of, 154 Bichromate solutions, 154 Blood-vessels, distribution of, 10 capacity of, 20 coats of, 18 nutrient, 24 Boll's method for neuroglia, 147 Borax carmine, 156 Broca's estimates of capacity, 59 Bucknill's specific gravity test, 63 Canada balsam 159 Capacity, arterial, 20 cranial, 57 Carmine staining fluids, 155 staining process, 120 Cements, list of, 159 Central medulla, 133 Chrome hardening, 102 Chromic acid, 105, 153 Cicatricial tissue, 44 Circle of Willis, 16 Colour of cortex, 45 Compound pigments, 128, 157 Consistence, estimation of, 29 reductions in, 31 augmented, 43 Convolutions of brain, 75 synonyms of, 78 Cortex cerebelli, staining, 132 cerebri, staining, 131 congestion of, 52 ganglion-cells of, 145 Cranial capacity, 57 D Dammar mounting medium, 159 Danilewski's method for weight, 07 Dissection of brain, 69 Dissociation of nervous tissue, 144 cells in cortex, 145 rapid method of, 145 Gerlach's method of, 144 Dissociating reagents, 158 Dura mater, examination of, 3 162 INDEX. E Ecker's s3monyms, 78 Embolic pluggiuyr of brain, 36 Eosin staining iluid, 131 Exner's osniic acid process, 105 EaiTant's solution, 159 Flowers' method for cranial capacity, 58 Freezing methods, 137 microtomes, ether, 92 — 95 Eutherford's, 90, 95 Williams', 98 Fresh brtiin, preparation of, 136 sections, staining, 140 G Ganglia of brain, staining, 142 Ganylion-cells of cortex, 122, 145 Gerlach's gold and potassium solution, 158 method of dissociation, 144 Gravimetric methods, 60 H Hajmatoxylin dye, 156 staining, process of, 116 Hamilton's methods of hardening, 104 hardening solutions, 154 Hardened brain, preparation of, 100 Hardening by chrome salts, 102 by osmium, 105 reagents, list of, 153 Imbedding mixtures, 108 process of, 107 Iodine green reagent, 131 Iodized serum, 158 K Kitton's lead cement, 159 Kleinenberg's hgematoxylin dye, 117 picric acid solution, 154 List of apparatus for section-cutting, 114 for staining and mounting-, 135 solutions for hardening, 153 dissociating, 158 mounting, 159 staining, 155 Logwood staining reagent, 155 M Macerating reagents, 158 Magenta dye, 157 Medulla oblongata, 134 Medulla, staining of central, 133 Membranes, examination of, 1 — 14 Methods of preparation, 86 Microtome, ether freezing, 92, 95 imbedding, 89 Ranvier's, 90 Eoy's, 91 Eutherford's, 90, 95 Schiefferdecker's, 91 Stirling's, 90 Williams', 98 Mierzejewski, method for neuroglia, 148 Minot's hfematoxylin dye, 116 Mounting fresh tissues, 143 hardened tissues, 115 media, 159 Miiller's fluid, 153 N Neuroglia, examination of, 147 hypertrophy of, 44 Osmic acid, process of hardening by, 105 staining by, 130 Pallor of cortex, 46 Paraffin mass for imbedding, 108 cast of cranium, 58 Physical properties of cerebral sub- stance, 26 Pia mater, examination of, 9 vessels of, 22 INDEX. 163 Picric acid solutions, 153,154 Picro- aniline staining, 130 Picro-cannine reagent, 156 staining, 124 Pigments, compound, 12S Pons, staining of, 134 Potassitun bichromate solutions, 1-3 3, 154 Preparation of fresh tissues, 136 of hardened tissues, 100 Pressiu'e, residts of intra-cranial, 54 intra-thoracic, 54 Puncta vasculosa, 53 Putrefactive changes, 31 Q Quekett Club microtome, 98 R Ranvier's method for neuroglia, 147 microtome, 90 picro-carmine dye, 156 Reaction of aniline blue-black, 126 carmine, 122 hfematoxylin , 119 osmic acid, 128 picro-carmine, 124 Reagents, list of, 153 Reference to photographs, 77 Roy's microtome, 91 Rutherford's hardening fluid, 154 microtome, 90, 95 rosanilin dye, 157 S Sankey's aniline solution, 125 specific gravity test, 63 Schieff erdecker' s mici'otome, 91 Sclerosis of nervous centres, 44 Section-blade, 112 Section-cutting, 110, 137 Sections, prei)aration of hardened, 115 preparation of fresh, 140 Silver lactate, 158 Sinuses of skidl, 5 Softening, indications of, 32 ischsemic, 33 yeUow, 37 inflammatory, 38 oedematous, 41 Special regions, staining of, 131 Specific gravity of brain, 62 Staining reagents, list of, 155 methods, 115, 140 Stevenson's displacement apparatus, 65 Stii-ling's microtome, 90 Siunniary of hardening methods, 106 Synonyms of convolutions, 78 Thiersch's carmine dye, 155 Topography of brain, superficial, 75 Tuke, method of estimating cranial capacity by Dr. Hack, 57 Vault of cerebrum, examination of, 4 Venous sinuses, 5 Volume of brain, 55 Volumetric methods, 55 W Weight of brain, absolute, 61 dift'erential, 67 specific, 62 Williams' microtome, 98 Zinc cement, 160 Zones, congested cortical, 52 Pardon and Sons, Printers, Paternoster Row, London. Catalogue B] Loftdon, II, Ne%v Burlington Street October, 1887 SELECTION FROM J. k A. CHURCHILL'S GENERAL CATALOGUE COMPRISING ALL RECENT WORKS PUBLISHED BY THEM ON THE ftKT A^D SCIENCE OF MEDICINE N.B. — As far as possible, this List is arranged in the order in which medical study is usually pursued. J. & A. CHURCHILL publish for the following Institutions and Public Bodies:— ROYAL COLLEGE OF SURGEONS. CATALOGUES OF THE MUSEUM. Twenty-three separate Catalogues (List and Prices can be obtained of J. &. A. Churchill). GUY'S HOSPITAL. REPORTS BY THE MEDICAL AND SURGICAL STAFF. Vol. XXVIIL, Third Series. 7s. 6d. FORMULA. USED IN THE HOSPITAL IN ADDITION TO THOSE IN THE B.P. IS. 6d. LONDON HOSPITAL. PHARMACOPCEIA OF THE HOSPITAL. 3s. CLINICAL LECTURES AND REPORTS BY THE MEDICAL AND SURGICAL STAFF. Vols. I. to IV. 7s. 6d. each. ST. BARTHOLOMEW'S HOSPITAL. CATALOGUE OF THE ANATOMICAL AND PATHOLOGICAL MUSEUM. Vol. I.— Pathology. 15s. Vol. II.— Teratology, Anatomy and Physiology, Botany, ys. 6d. ST. GEORGE'S HOSPITAL. REPORTS BY THE MEDICAL AND SURGICAL STAFF. The last Volume (X.) was issued in 1880. Price 7s. 6d. CATALOGUE OF THE PATHOLOGICAL MUSEUM. 15s. SUPPLEMENTARY CATALOGUE {1882). 5s. ST. THOMAS'S HOSPITAL. REPORTS BY THE MEDICAL AND SURGICAL STAFF. Annually. Vol. XV., New Series. 7s. 6d. MIDDLESEX HOSPITAL. CATALOGUE OF THE PATHOLOGICAL MUSEUM. 12s. WESTMINSTER HOSPITAL. REPORTS BY THE MEDICAL AND SURGICAL STAFF. Annually. Vol. II. 6s. ROYAL LONDON OPHTHALMIC HOSPITAL. REPORTS BY THE MEDICAL AND SURGICAL STAFF. Occasionally. Vol. XL, Part IV. 5s. OPHTHALMOLOGICAL SOCIETY OF THE UNITED KINGDOM. TRANSACTIONS. Vol. VI. I2S. 6d. MEDICO-PSYCHOLOGICAL ASSOCIATION. JOURNAL OF MENTAL SCIENCE. Quarterly, 3s. 6d. each, or 14s. per annum. PHARMACEUTICAL SOCIETY OF GREAT BRITAIN. PHARMACEUTICAL JOURNAL AND TRANSACTIONS. Every Saturday. 4d. each, or 20s. per annum, post free. BRITISH PHARMACEUTICAL CONFERENCE. YEAR BOOK OF PHARMACY. In December. los. BRITISH DENTAL ASSOCIATION. JOURNAL OF THE ASSOCIATION AND MONTHLY REVIEW OF DENTAL SURGERY. On the 15th of each Month. 6d. each, or 7s. per annum, post free. A SELECTION FROM J. & A. CHURCHILL'S GENERAL CATALOGUE, COMPRISING ALL RECENT WORKS PUBLISHED BY THEM ON THE ART AND SCIENCE OF MEDICINE. N.B. — J. 4* ^' ChurchilVs Descriptive List of Works on Chemistry, Materia Medica, Pharmacy, Botany, Photography, Zoology, the Microscope, and other Branches of Science, can be had on application. Practical Anatomy : A Manual of Dissections. By Christopher Heath, Surgeon to University College Hospital. Sixth Edition. Revised by RiCKMAN J. GODLEE, M.S. Lond., F.R.C. S., Demonstrator of Anatomy in University College, and Assistant Surgeon to the Hospital. Crown 8vo, with 24 Coloured Plates and 274 Engravings, 15s. ■Wilson's Anatomist's Vade- Mecum. Tenth Edition. By George Buchanan, Professor of Clinical Surgery in the University of Glasgow; and Henry E. Clark, M.R.C.S., Lecturer on Ana- tomy at the Glasgow Royal Infirmary School of Medicine. Crown 8vo, with 450 Engravings (including 26 Coloured Plates), i8s. Braune's Atlas of Topographi- cal Anatomy, after Plane Sections of Frozen Bodies. Translated by Edward Bellamy, Surgeon to, and Lecturer on Anatomy, &c., at, Charing Cross Hos- pital. Large Imp. 8vo, with 34 Photo- lithographic Plates and 46 Woodcuts, 40s. An Atlas of Human Anatomy. By Rickman J. Godlee, M.S., F.R.C.S., Assistant Surgeon and Senior Demonstrator of Anatomy, University College Hospital. With 48 Imp. 4to Plates (1x2 figures), and a volume of Ex- planatory Text, 8vo, £^ 14s. 6d. Harvey's (Wm.) Manuscript Lectures, Prelectiones Anatomise Uni- versalis. Edited, with an Autotype repro- duction of the Original, by a Committee of the Royal College of Physicians of London. Crown 4to, half bound in Persian, 52s. 6d, Anatomy of the Joints of Man. By Henry Morris, Surgeon to, and Lecturer on Anatomy and Practical Sur- gery at, the Middlesex Hospital. 8vo, with 44 Lithographic Plates (several being coloured) and 13 Wood Engravings, 1 6s. Manual of the Dissection of the Human Body. By Luther Holden, Consulting Surgeon to St. Bartholomew's Hospital. Edited by John Langton, F.R.C.S., Surgeon to, and Lecturer on Anatomy at, St. Bartholomew's Hos- pital. Fifth Edition. 8vo, with 208 Engravings. 20s. By the same Author. Human Osteology. Seventh Edition, edited by Charles Stewart, Conservator of the Museum R.C.S.,andR.W.REiD,M.D.,F.R.C.S., Lecturer on Anatomy at St. Thomas's Hospital. 8vo, with 59 Lithographic Plates and 75 Engravings. i6s. Also. Landmarks, Medical and Surgi- cal. Fourth Edition. 8vo. [/« the Press. The Student's Guide to Surgical Anatomy. By Edward Bellamy, F.R.C.S. and Member of the Board of Examiners. Third Edition. Fcap. 8vo, with 81 Engravings. 7s. 6d. The Anatomical Remembran- cer ; or, Complete Pocket Anatomist. Eighth Edition. 32mo, 3s. 6d. Diagrams of the Nerves of the Human Body, exhibiting their Origin, Divisions, and Connections, with their Distribution to the Various Regions of the Cutaneous Surface, and to all the Muscles. By W. H. Flower, C.B., F.R.S., F.R.C.S. Third Edition, with 6 Plates. Royal 410, 12s. J. ^- A. CHURCHILL'S RECENT WORKS. General Pathology. An Introduction to. By John Bland Sutton, F.R.C.S., Sir E. Wilson Lecturer on Pathology, R.C.S. ; Assistant Surgeon to, and Lecturer on Anatomy at, Middlesex Hospital. 8vo, "with 149 En- gravings, 14s. Atlas of Pathological Anatomy. By Dr. Lancereaux. Translated by W. S. Greenfield, M.D., Professor of Pathology in the University of Edin- burgh. Imp. 8vo, with 70 Coloured Plates, ^5 5s. A Manual of Pathological Ana- tomy. By C. Handfield Jones, M.B., F.R.S., and E. H. Sieveking, M.D., F.R.C.P. Edited by J. F. Payne, M.D., F.R.C.P., Lecturer on General Pathology at St. Thomas's Hospital. Second Edition. Crown 8vo, with 195 Engravings, i6s. Post-mortem Examinations : A Description and Explanation of the Method of Performing them, with especial reference to Medico-Legal Practice. By Prof. ViRCHOW. Translated by Dr. T. P. Smith. Second Edition. Fcap. 8vo, with 4 Plates, 3s. 6d. The Human Brain : Histological and Coarse Methods of Re- search. A Manual for Students and Asylum Medical Officers. ByW. Bevan Lewis, L.R.C.P. Lond., Medical Super intendent. West Riding Lunatic Asylum. 8vo, with Wood Engravings and Photo- graphs, 8s. Manual of Physiology : For the use of Junior Students of Medi- cine. By Gerald F. Yeo, M.D., F.R.C.S., Professor of Physiology in King's College, London, Second Edition. Crown 8vo, with 318 Engravings, 14s. Principles of Human Physi- ology. By W. B. Carpenter, C.B., M.D., F.R.S. Ninth Edition. By Henry Power, M.B., F. R.C.S. 8vo, with 3 Steel Plates and 377 Wood Engrav- ings, 31S. 6d. Elementary Practical Biology : Vegetable. By Thomas W. Shore, M.D., B.Sc. Lond., Lecturer on Com- parative Anatomy at St. Bartholomew's Hospital. 8vo, 6s. Histology and Histo-Chemistry of Man. By Heinrich Prey, Pro- fessor of Medicine in Zurich. Translated by Arthur E. J. Barker, Assistant Surgeon to University College Hospital. 8vo, with 608 Engravings, 21s. AText-Bookof Medical Physics, for Students and Practitioners. By J. C. Draper, M.D., LL.D., Professor of Physics in the University of New York. With 377 Engravings. 8vo, i8s. Medical Jurisprudence : Its Principles and Practice. By Alfred S. Taylor, M.D., F.R.C.P., F.R.S. Third Edition, by Thomas Stevenson, M.D., F.R.C.P., Lecturer on Medical Jurisprudence at Guy's Hospital. 2 vols. 8vo, with 1 88 Engravings, 31s. 6d. By the same Authors. A Manual of Medical Jurispru- dence. Eleventh Edition. Crown 8vo, with 56 Engravings, 14s. Also. Poisons, In Relation to Medical Jurisprudence and Medicine. Third Edition. Crown 8vo, with 104 Engravings, i6s. Lectures on Medical Jurispru- dence. By Francis Ogston, M.D., late Professor in the University of Abet' deen. Edited by Francis Ogston, jun., M.D. 8vo, with 12 Copper Plates, i8s. The Student's Guide to Medical Jurisprudence. By John Aber- CROMBiE, M.D., F.R.C.P., Lecturer on Forensic Medicine to Charing Cross Hospital. Fcap. 8vo, 7s. 6d. Influence of Sex in Disease. By W. Roger Williams, F. R.C.S., Surgical Registrar to the Middlesex Hos- pital. 8vo, 3s. 6d. Microscopical Examination of Drinking "Water and of Air. By J. D. Macdonald, M.D., F.R.S., Ex- Professor of Naval Hygiene in the Army Medical School. Second Edition. 8vo, with 25 Plates, 7s. 6d. Pay Hospitals and Paying "Wards throughout the "World. By Henry C. Burdett. 8vo, 7s. By the same Author. Cottage Hospitals — General, Fever, and Convalescent : Their Progress, Management, and Work. .Second Edition, with many Plans and Illustra- tions. Crown Svo, 14s. Hospitals, Infirmaries, and Dis- pensaries : Their Construction, Inte- rior Arrangement, and Management; with Descriptions of existing Institutions, and 74 Illustrations. By F. Oppert, M.D., M.R.C.P.L, Second Edition. Royal Svo, I2s. Hospital Construction and Management. By F. J. Mouat, M.D., Local Government Board Inspec- tor, and H. Saxon Snell, Fell. Roy. Inst. Brit. Architects. In 2 Parts, 4to, 15s. each; or, the whole work bound in half calf, with large Map, 54 Lithographic Plates, and 27 Woodcuts, 35s. Public Health Reports. By Sir John Simon, C.B., F.R.S. Edited by Edward Seaton, M.D., F.R.C.P. 2 vols. Svo, with Portrait, 36s. J. .S' A. CHURCHILL- S RECENT JVORA'S. 5 A Manual of Practical Hygiene. By F. A. Parkes, M.D., F.R.S. Seventh Edition, by F. DE Chaumont, M.D., F.R.S., Professor of Military Hygiene in the Army Medical School. 8vo, with 9 Plates and lOO Engravings, i8s. A Handbook of Hygiene and Sanitary Science, By Geo. Wilson, M.A., M.D., F.R.S.E., Medical Officer of Health for Mid-Warwickshire. Sixth Edition. Crown 8vo, with Engravings, los. 6d. Bj' tJie same Author. Healthy Life and Healthy Dwellings : A (juide to Personal and Domestic Hygiene. Fcap. 8vo, 5s. Sanitary Examinations Of Water, Air, and Food. A Vade- Mecum for the Medical Officer of Health. By Cornelius B. Fox, M.D., F.R.C.P. Second Edition. Crown 8vo, with IIO Engravings, 12s. 6d. Dangers to Health : A Pictorial Guide to Domestic Sanitary Defects. By T. Pridgin Teale, M.A., Surgeon to the Leeds General Infirmaiy. Fourth Edition. Svo, with 70 Lithograph Plates (mostly coloured), ids. Manual of Anthropometry : A Guide to the Measurement of the Human Body, containing an Anthropo- metrical Chart and Register, a Systematic Table of Measurements, &c. By Charles Roberts, F.R.C.S. 8vo, with numerous Illustrations and Tables, 8s. 6d. By the same Author. Detection of Colour-Blindness and Imperfect Eyesight. Svo, with a Table of Coloured Wools, and Sheet of Test-tyj^es, 5s. Illustrations of the Influence of the Mind upon the Body in Health and Disease : Designed to elucidate the Action of the hnagination. By Daniel Hack Tuke, M.D., F.R.C.P., LL.D. Second Edition. 2 vols, crown Svo, 15s. By the same Author. Sleep-Walking and Hypnotism. Svo, 5s. A Manual of Psychological Medicine. With an Appendix of Cases. By John C. Bucknill, M.D., F.R.S., and D. Hack Tuke, M.D., F.R.C.P. Fourth Edition. Svo, with 12 Plates (30 Figures) and Engravings, 25s. Mental Affections of Childhood and Youth (Lettsomian Lectures for 18S7, Sec). By J. Langdon Down, M.D., F.R.C.P., Senior Physician to the London Hospital. Svo, 6s. Private Treatment of the Insane as Single Patients. By Edward East, M.R.C.S., L.S.A. Crown Svo, 2s. 6d. Mental Diseases. Clinical Lectures. By T. S. Clouston, M.D., F.R.C.P. Edin., Lecturer on Mental Diseases in the University of Edinburgh. Second Edition. Crown Svo, wuh 8 Plates (6 Coloured), 12s. 6d. Manual of Midwifery. By Alfred L. Galaiun, M.A., M.D., F.R.C.P., Obstetric Physician to, and Lecturer on Midwifery, &c. at, Guy's Hospital. Crown Svo, with 227 En- gravings, 15s. The Student's Guide to the Practice of Mid'wifery. By D. Lloyd Roberts, M.D., F.R.C.P., Lec- turer on Clinical Midwif^ery and Diseases of Women at the Owens College ; Obstetric Physician to the Manchester Royal In- firmary. Third Edition. Fcap. Svo, with 2 Coloured Plates and 127 Wood Engrav- ings, 7s. 6d. Lectures on Obstetric Opera- tions : Including the Treatment of Haemorrhage, and forming a Guide to the Management of Difficult Labour. By Robert Barnes, M.D., F.R.C.P., Consulting Obstetric Physician to St. George's Hospital. Fourth Edition. Svo, with 121 Engravings, 12s. 6d. By the same Author. A Clinical History of Medical and Surgical Diseases of 'Women. Second Edition. Svo, with iSi Engravings, 28s. Clinical Lectures on Diseases of 'Women : Delivered in St. Bartho- lomew's Hospital, by J. Matthews Duncan, M.D., LL.D., F.R.S. Third Edition. Svo, 1 6s. By the same Author. Sterility in Woman. Being the Gulstonian Lectures, delivered in the Royal College of Physicians, in Feb., 1S83. 8vo, 6s. Notes on Diseases of W^omen : Specially designed to assist the Student in preparing for Examination. By J. J. Reynolds, L.R.C.P., M.R.C.S. Third Edition. Fcap. Svo, 2s. 6d. By the same Author. Notes on Midwifery : Specially designed for Students preparing for Examination. Second Edition. Fcap. Svo, with I S Engravings, 4s. Dysmenorrhoea, its Pathology and Treatment. By Heywood Smith, M.D. Crown Svo, with Engravings, 4s. 6d. A Manual of Obstetrics. By A. F. A. King, A.M., M.D., Pro- fessor of Obstetrics, &c., in the Columbian University, Washington, and the Univer- sity of Vermont. Third Edition. Crown Svo, with 102 Engravings, 8s. J. 4'- A. CHURCHILL S RECENT WORKS. The Student's Guide to the Diseases of 'Women. By Alfred L. Galabin, M.D., F.R.C.P., Obstetric Physician to Guy's Hospital. Fourth Edi- tion. Fcap.Svo, with 94 Engravings, 7s.6cl. West on the Diseases of "Women. Fourth Edition, revised by the Author, with numerous Additions by J. Matthews Duncan, M.D., F.R.C.P., F.R.S.E., Obstetric Physician to St. Bar- tholomew's Hospital. 8vo, i6s. Obstetric Aphorisms : For the Use of Students commencing Midwifery Practice. By Joseph G. SwAYNE, M.D. Eighth Edition. Fcap. 8vo, with Engravings, 3s. 6d. Handbook of Midwifery for Mid- -wives : By J. E. Burton, L.R.C.P. Lond., Surgeon to the Hospital for Women, Liverpool. Second Edition. With Engravings. Fcap. 8vo, 6s. A Handbook of Uterine Thera- peutics, and of Diseases of Women. By E. J. Tilt, M.D., M.R.C.P. Fourth Edition. Post 8vo, ids. By the same A tit ho?: The Change of Life In Health and Disease : A Clinical Treatise on the Diseases of the Nervous System incidental to Women at the De- clineofLife. Fourth Edition. 8vo, los. 6d. Diseases of the Uterus, Ovaries, and Fallopian Tubes : A Practical Treatise by A. Courty, Professor of Clinical Surgery, Montpellier. Translated from Third Edition by his Pupil, Agnes McLaren, M.D., M.K.Q.C.P.I., with Preface by J. Matthews Duncan, M.D., F. R. C. P. 8vo, with 424 Engravings, 24s. The Female Pelvic Organs : Their Surgery, Surgical Pathology, and Surgical Anatomy. In a Series of Coloured Plates taken from Nature ; with Com- mentaries, Notes, and Cases. By Henry Savage, M.D., F.R.C.S. , Consulting Officer of the Samaritan Free Hospital. Fifth Edition. Roy. 4to, with 17 Litho- graphic Plates (15 coloured) and 52 Wood- cuts, £1 15s. A Practical Treatise on the Diseases of "Women. By T. Gail- lard Thomas, M.D., Professor of Diseases of Women in the College of Physicians and Surgeons, New York. Fifth Edition. Roy. 8vo, with 266 En- gravings, 25s. Backward Displacements of the Uterus and Prolapsus Uteri : Treatment by the New Method of Short- ening the Round Ligaments. By Wil- liam Alexander, M.D., M.Ch.Q.U.L, F. R. C. S. , Surgeon to the Liverpool Infir- mary. Crown 8vo, with Engravings, 3s. 6d. Gynaecological Operations : (Handbook of). ByALBAN H. G. Doran, F.R.C.S., Surgeon to the Samaritan Hos- pital. Svo, with 167 Engravings, 15s. Abdominal Surgery. By J. Greig Smith, M.A., F.R.S.E., Surgeon to the Bristol Royal Infirmary. Svo, with 43 Engravings, 15s. Ovarian and Uterine Tumours : Their Pathology and Surgical Treatment. By Sir T. Spencer Wells, Bart., F.R.C.S., Consulting Surgeon to the Samaritan Hospital. Svo, with En- gravings, 2 Is. By the same Author. Abdominal Tumours: Their Diagnosis and .Surgical Treatment. Svo, with Engravings, 3s. 6d. The Student's Guide to Diseases of Children. ByjAs. F. Goodhart, M.D., F.R.C.P., Physician to Guy's Hospital, and to the Evelina Hospital for Sick Children. Second Edition. Fcap. Svo, I OS. 6d. Diseases of Children. For Practitioners and Students. By W. H. Day, M.D., Physician to the Sama- ritan Hospital. Second Edition. Crown Svo, I2S. 6d. A Practical Treatise on Disease in Children. By Eustace Smith, M.D., Physician to the King of the Belgians, Physician to the East London Hospital for Children. Svo, 22s. By the same Aiitlior. Clinical Studies of Disease in Children. Second Edition. Post Svo, 7s. 6d. Also. The "Wasting Diseases of Infants and Children. Fourth Edition. Post Svo, Ss. 6d. A Practical Manual of the Diseases of Children. With a For- mulary. By Edward Ellis, M.D. Fifth Edition. Crown Svo, los. A Manual for Hospital Nurses and others engaged in Attending on the Sick. By Edward J. Domville, Surgeon to the Exeter Lying-in Charity. Fifth Edition. Crown Svo, 2s. 6d. A Manual of Nursing, Medical and Surgical. By Charles J. Cul- lingworth, M.D., PhysiciantoSt. Mary's Hospital, Manchester. Second Edition. Fcap. Svo, with Engravings, 3s. 6d. By the same Author. A Short Manual for Monthly Nurses. Second Edition. Fcap. Svo, is. 6d. Diseases and their Commence- ment. Lectures to Trained Nurses. By Donald W. C. Hood, M.D., M.R.C.P., Physician to the West London Hospital. Crown Svo, 2s. 6d. J. i^ A. CHURCHILLS RECENT WORKS. Notes on Fever Nursing. By J. W. Allan, M.B., Physician, Superintendent Glasgow Fever Hospital. Crown 8vo, with Engravings, 2s. 6d. By the same Author. Outlines of Infectious Diseases : For the use of Clinical Students. Fcap. 8vo. Hospital Sisters and their Du- ties. By Eva C. E. Luckes, Matron to the London Hospital. Crown 8vo, 2s. 6d. Infant Feeding and its Influ- ence on Life ; By C. H. F. Routh, M. D. , Physician to the Samaritan Hospital. Fourth Edition. Fcap. 8vo. [Preparing: Manual of Botany : Including the Structure, Classification, Properties, Uses, and Functions of Plants. By Robert Bentley, Professor of Bo- tany in King's College and to the Phar- maceutical Society. Fifth Edition. Crown 8vo, with 1,178 Engravings, 15s. By the same Author. The Student's Guide to Struc- tural, Morphological, and Phy- siological Botany. With 660 En- gravings. Fcap. Svo, 7s. 6d. Also. The Student's Guide to Syste- matic Botany, including the Classi- fication of Plants and Descriptive Botany. Fcap. 8vo, with 350 Engravings, 3s. 6d. Medicinal Plants : Being descriptions, with original figures, of the Principal Plants employed in Medicine, and an account of their Pro- perties and Uses. By Prof. Bentley and Dr. H. Trimen. In 4 vols., large Svo, with 306 Coloured Plates, bound in Half Morocco, Gilt Edges, ;i{^ii lis. The National Dispensatory : ContainingtheNatural History, Chemistry, Pharmacy, Actions and Uses of Medicines. By Alfred Stills, M.D., LL.D., and John M. Maisch, Ph.D. Fourth Edi- tion. Svo, with 311 Engravings, 36s. Royle's Manual of Materia Medica and Therapeutics. Sixth Edition, including additions and altera- tions in the B.P. 1885. By JOHN Harley, M.D., Physician to St. Thomas's Hospital. Crown Svo, with 139 Engravings, 15s. Materia Medica and Therapeu- tics : Vegetable Kingdom — Organic Compounds — Animal Kingdom. By Charles D. F. Phillips, M.D., F.R.S. Edin., late Lecturer on Materia Medica and Therapeutics at the Westminster Hospital Medical School. Svo, 25s. The Student's Guide to Materia Medica and Therapeutics. By John C. Thorowgood, M.D., F.R.C.P. Second Edition. Fcap. Svo, 7s. Materia Medica. A Manual for the use of Students. By Isambard Owen, M.D., F.R.C.P., Lec- turer on Materia Medica, &c., to St. George's Hospital. Second Edition. Crown Svo, 6s. 6d. The Pharmacopoeia of the Lon- don Hospital. Compiled under the direction of a Committee appointed by the Hospital Medical Council. Fcap. Svo, 3s. A Companion to the British Pharmacopceia. By Peter Squire, Revised by his Sons, P. W. and A. H. Squire. 14th Edition. Svo, los. 6d. By the same Authors. The Pharmacopoeias of the Lon- don Hospitals, arranged in Groups for Easy Reference and Comparison. Fifth Edition. iSmo, 6s. The Prescriber's Pharmacopceia: The Medicines arranged in Classes accord- ing to their Action, with their Composi- tion and Doses. By Nestor J. C. Tirard, M.D., F.R.C.P., Professor of Materia Medica and Therapeutics in King's College, London. Sixth Edition. 32mo, bound in leather, 3s. A Treatise on the Principles and Practice of Medicine. Sixth Edition. By Austin Flint, M.D., W.H. Welch, M.D., and Austin Flint, jun., M.D. Svo, with Engravings, 26s. Climate and Fevers of India, with a series of Cases (Croonian Lec- tures, 1882). By Sir Joseph Fayrer, K.C.S.I., M.D. Svo, with 17 Tem- perature Charts, 12s. Family Medicine for India. A Manual. ByWiLLiAMj. Moore, M.D. , CLE., Honorary Surgeon to the Viceroy of India. Published under the Authority of the Government of India. Fifth Edition. Post Svo, with Engravings. \_In the Press. By the same Author. A Manual of the Diseases of India : With a Compendium of Diseases generally. Second Edition. Post Svo, los. Also. Health- Resorts for Tropical Invalids, in India, at Home, and Abroad. Post Svo, 5s. Practical Therapeutics : A Manual. By Edward J. Waring, CLE., M.D., F.R.C.P., and Dudley W. Buxton, M.D., B.S. Lond. Fourth Edition. Crown Svo, 14s. By the same Attthor. Bazaar Medicines of India, And Common Medical Plants : With Full Index of Diseases, indicating their Treat- ment by these and other Agents procur- able throughout India, &c. Fourth Edition. Fcap. Svo, 5s. J. i^- A. CHURCHILL'S RECENT WORKS. A Commentary on the Diseases of India. By Norman Chevers, CLE., M.D., F.R.C.S., Deputy Sur- geon-General H.M. Indian Army. 8vo, 24s. The Principles and Practice of Medicine. By C. Hilton Fagge, M.D. Edited byP. H. Pye-Smith, M.D., F. R.C.P. , Physician to, and Lecturer on Medicine at, Guy's Hospital. 2 vols. 8vo, 1S60 pp. Cloth, 36s. ; Half Persian, 42s. The Student's Guide to the Practice of Medicine. By Mat- thew Charteris, M.D., Professor of Materia Medica in the University of Glasgow. Fourth Edition. P'cap. 8vo, with Engravings on Copper and Wood. 9s. Hooper's Physicians' Vade- Mecum. A Manual of the Principles and Practice of Physic. Tenth Edition. By W. A. Guy, F.R.C.P., F.R.S., and J. Harley, M.D., F.R.C.P. With 118 Engravings. P'cap. 8vo, 12s. 6d. The Student's Guide to Clinical Medicine and Case-Taking. By Francis Warner, M.D., F.R.C.P., Physician to the London Hospital. Second Edition. Fcap. 8vo, 5s. How to Examine the Chest : Being a Practical Guide for the use of Students. By Samuel West, 1\LD., F.R.C.P., Physician to the City of London Hospital for Diseases of the Chest ; Assistant Physician to St. Bartholomew's Hospital. With 42 Engravings. Fcap. 8vo, 5s. The Contagiousness of Pulmo- nary Consumption, and its Anti- septic Treatment. By J. Burney Yeo, M.D., Physician to Iving's College Hospital. Crown 8vo, 3s. 6d. The Operative Treatment of In- tra-thoracic Effusion. Fothergillian Prize Essay. By Norman Porritt, L.R.C.P. Lond., M.R.C.S. With En- gravings. Crown 8vo, 6s. Diseases of the Chest : Contributions to their Clinical History, Pathology, and Treatment. By A. T. Houghton Waters, M.D., Physician to the Liverpool Ixoyal Infirmary. Second Edition. 8vo, with Plates, 15s. Pulmonary Consumption : A Practical Treatise on its Cure with Medicinal, Dietetic, and Hygienic Remedies. By James Weaver, M.D., L.R.C.P. Crown Svo, 2s. Croonian Lectures on Some Points in the Pathology and Treatment of Typhoid Fever. By William Cayley, M.D., F.R.C.P., Physician to the Middlesex and the London Fever Hospitals. Crown Svo, 4s. 6d. The Student's Guide to Medical Diagnosis. By Samuel Fenwick, M.D., F.R.C.P., Physician to the Lon- don Hospital, and Bedford Fenwick, M.D., M. R.C.P. Sixth Edition. Fcap. Svo, with 114 Engravings, 7s. By the same Author. The Student's Outlines of Medi- cal Treatment. Second Edition. Fcap. Svo, 7s. Also. On Chronic Atrophy of the Stomach, and on the Nervous Affections of the Digestive Organs. Svo, Ss. The Microscope in Medicine. By Lionel S. Beale, M.B., F.R.S., Physician to King's College Hospital. Fourth Edition. Svo, with 86 Plates, 21s. Also. On Slight Ailments : Their Nature and Treatment. Second Edition. Svo, 5s. Medical Lectures and Essays. By George Johnson, M.D., F.R.C.P., F. R. S., Consulting Physician to King's College Hospital. Svo. The Spectroscope in Medicine. By Charles A. MacMunn, B.A., M.D. Svo, with 3 Chromo-lithographic Plates of Physiological and Pathological Spectra, and 13 Engravings, 9s. Notes on Asthma : Its Forms and Treatment. By John C. Thorowgood, M.D., Physician to the Hospital for Diseases of the Chest. Third Edition. Crown Svo, 4s. 6d. What is Consumption ? By G. W. Hambleton, L.K.Q.C.P.I. Crown Svo, 2s. 6d. Winter Cough (Catarrh, Bronchitis, Emphysema, Asth- ma). By Horace Dobell, M.D., Consulting Physician to the Royal Hos- pital for Diseases of the Chest. Third Edi- tion. Svo, with Coloured Plates, los. 6d. By the same Autlior. Loss of Weight, Blood-Spitting, and Lung Disease. Second Edition. Svo, with Chromo-lithograph, los. 6d. Also. The Mont Dore Cure, and th^ Proper Way to Use it. Svo, 7s. 6d. Vaccinia and Variola : A Study of their Life History. By JoilN B. BuiST, M.D., F.R.S.E., Teacher of Vaccination for the Local Government Board. Crown Svo, with 24 Coloured Plates, 7s. 6d. Treatment of Some of the Forms of Valvular Disease of the Heart. By A. E. Sansom, M.D., F.R.C.P., Physician to the London Hospital. Second Edition. Fcap. Svo, with 26 Engravings, 4s. 6d. J. ^- A. CHURCHILL'S RECENT WORKS. Diseases of the Heart and Aorta : Clinical Lectures. By G. W. Balfour, M.p., F.R.C.P., F.R.S. Eclin., late Senior Physician and Lecturer on Clinical Medicine, Royal Infirmary, Edinburgh. Second Edition. 8vo, with Chromo-litho- graph and Wood Engravings, I2s. 6d. Medical Ophthalmoscopy : A Manual and Atlas. By William R. GOWERS, M.D., F.R.C.P., Professor of Clinical Medicine in University College, and Physician to the Hospital. Second Edition, with Coloured Autotype and Lithographic Plates and Woodcuts. 8vo, i8s. By the same Aitthor. Pseudo-Hypertrophic Muscular Paralysis : A Clinical Lecture. Svo, with Engravings and Plate, 3s. 6d. Also. Diagnosis of Diseases of the spinal Cord. Third Edition. Svo, with Engravings, 4s. 6d. Also. Diagnosis of Diseases of the Brain. Second Edition. Svo, with Engravings, 7s. 6d. Also. A Manual of Diseases of the Nervous System. Vol. I. Diseases of the Spinal Cord and Nerves. Roy. Svo, with 171 Engravings(manyfigures), I2s.6d. Diseasesof the Nervous System. Lectures delivered at Guy's Hospital. By Samuel WiLKs, M.D., F.R.S. Second Edition. Svo, iSs. Diseases of the Nervous System: Especially in Women. By S. Weir Mitchell, ]\LD., Physician to the Phila- delphia Infirmary for Diseases of the Nervous System. Second Edition. Svo, with 5 Plates, 8s. Nerve Vibration and Excitation, as Agents in the Treatment of Functional Disorder and Organic Disease. By J. Mortimer Granville, M.D. Svo, 5s. By the same Author. Gout in its Clinical Aspects. Crown Svo, 6s. Regimen to be adopted in Cases of Gout. By Wilhelm Ebstein, M.D., Professor of Clinical Medicine in Gottingen. Translated by John Scott, M.A., M.B. Svo, 2s. 6d. Diseases of the Nervous System. Clinical Lectures. By Thomas Buzzard, M.D., F.R.C.P., Physician to the National Hospital for the Paralysed and Epileptic. With Engravings, Svo. 15s. By the same Aitthor. Some Forms of Paralysis from Peripheral Neuritis : of Gouty, Alcoholic, Diphtheritic, and other origin. Crown Svo, 5s. Diseases of the Liver: With and without Jaundice. By George Harley, M.D., F.R.C.P., F.R.S. Svo, with 2 Plates and 36 Engravings, 21s, By the same Author. Inflammations of the Liver, and their Sequelae. Crown Svo, with Engravings, 5s. Gout, Rheumatism, And the Allied Affections ; with Chapters on Longevity and .Sleep. By Peter Hood, M.D. Third Edition. Crown Svo, 7s. 6d. Diseases of the Stomach : The Varieties of Dyspepsia, their Diagnosis and Treatment. By S. O. Habershon, M.D., F.R.C.P. Third Edition. Crown Svo, 5s. By the same AiUJior. Pathology of the Pneumo- gastric Nerve : Lumleian Lectures for 1S76. Second Edition. Post Svo, 4s. Also. Diseases of the Abdomen, Comprising those of the Stomach and other parts of the Alimentary Canal, Oesopha- gus, Ctecum, Intestines, and Peritoneum. Third Edition. Svo, with 5 Plates, 21s. Also. Diseases of the Liver, Their Pathology and Treatment. Lett- somian Lectures. Second Edition. Post Svo, 4s. Acute Intestinal Strangulation, And Chronic Intestinal Obstruction (Mode of Death from). By Thomas Bryant, F. R.C.S., Senior Surgeon to Guy's Hospital. Svo, 3s. A Treatise on the Diseases of the Nervous System, By James Ross, JNLD., F.R.C.P., Assistant Physi- cian to the Manchester Royal Infirmary. .Second Edition. 2 vols. Svo, with Litho- graphs, Photographs, and 332 Woodcuts, 52s. 6d. By the same Author. Handbook of the Diseases of the Nervous System. Roy. Svo, with 184 Engravings, iSs. Also. Aphasia : Being a Contribution to the Subject of the Dissolution of .Speech from Cerebral Disease. Svo, with Engravings, 4s. 6d. Spasm in Chronic Nerve Disease. (Cnilstonian Lectures.) By Seymour J. Sharkey, M.A., M.B., F.R.C.P., Assistant Physician to, and Joint Lec- turer on Pathology at, St. Thomas's Plospital. Svo, with Engravings, 5s. On Megrim, Sick Headache, and some Allied Disorders : A Contribu- tion to the Pathology of Nerve Storms. By E. LiVEiNC, M.D., F.R.C.P. Svo, 15s. lO J. <§• A. CHURCHILL'S RECENT WORKS. Food and Dietetics, Physiologically and Therapeutically Con- sidered. By F. W. Pavy, M.D., F.R.S., Physician to Guy's Hospital. Second Edition. 8vo, 15s. By the same Author. Croonian Lectures on Certain Points connected -with Diabetes. 8vo, 4s. 6d. Headaches : Their Nature, Causes, and Treatment. By W. H. Day, M.D., Physician to the Samaritan Hospital. Fourth Edition. Crown 8vo, with Engravings. [/« the Press. Health Resorts at Home and Abroad. By Matthew Charteris, M.D., Physician to the Glasgow Royal Infirmary. Second Edition. Crown Svo, with Map, 5s. 6d. The Principal Southern and Swiss Health-Resorts : their Cli- mate and Medical Aspect. By William Marcet, M.D., F.R.C.P., F.R.S. With Illustrations. Crown Svo, 7s. 6d. Winter and Spring On the Shores of the Mediterranean. By Henry Bennet, M.D. Fifth Edition. Post Svo, with numerous Plates, Maps, and Engravings, 12s. 6d. By the same Author. Treatment of Pulmonary Con- sumption by Hygiene, CHmate, and Medicine. Third Edition. Svo, 7s. 6d. Medical Guide to the Mineral "Waters of France and its "Win- tering Stations. With a Special Map. ByA. ViNTRAS, M.D., Physician to the French Embassy, and to the French Hospital, London. Crown Svo, 8s. The Ocean as a Health-Resort : A Practical Handljook of the Sea, for the use of Tourists and Health-Seekers. By William S. Wilson, L.R.C.P. Second Edition, vi^ith Chart of Ocean Routes, «S:c. Crown Svo, 7s. 6d. Ambulance Handbook for Volun- teers and Others. By J. Ardavon Raye, L.K. & Q.C.P.I., L.Ri.C.S.1., late Surgeon to H.B.M. Transport No. 14, Zulu Campaign, and Surgeon E.I.R. Rifles. Svo, with 16 Plates (50 figures), 3s. 6d. Ambulance Lectures : To which is added a Nursing Lecture. By John M. H. Martin, Honorary Surgeon to the Blackburn Infirmary. Crown Svo, with 53 Engravings, 2s. Commoner Diseases and Acci- dents to Life and Limb : their Preventionand Immediate Treat- ment. By M. M. Basil, M.A., M.B., CM. Crown Svo, 2s. 6d. Handbook of Medical and Sur- gical Electricity. By Herbert TiBBiTS, M.D., F.R.C.P.E., Senior Physician to the West London Hospital for Paralysis and Epilepsy. Second Edition. Svo, with 95 Engravings, 9s. By the same Author. How to Use a Galvanic Battery in Medicine and Surgery. Third Edition. Svo, with Engravings, 4s. Also. A Map of Ziemssen's Motor Points of the Human Body : A Guideto Localised Electrisation. Mounted on Rollers, 35 x 21. With 20 Illustra- tions, 5s. ^4iso. Electrical and Anatomical De- monstrations. A Handbook for Trained Nurses and Masseuses. Crown Svo, with 44 Illustrations, 5s. Spina Bifida : Its Treatment by a New Method. By Jas. Morton, M.D., L.R.C.S.E., Pro- fessor of Materia Medica in Anderson's College, Glasgow. Svo, with Plates, 7s. 6d. Surgical Emergencies : Together with the Emergencies attendant on Parturition and the Treatment of Poisoning. ByW.PAULS\VAiN,F.R.C.S., Surgeon to the South Devon and East Corn- wall Hospital. Fourth Edition. Crown Svo, with 120 Engravings, 5s. Operative Surgery in the Cal- cutta Medical College Hospital. Statistics, Cases, and Comments. By Kenneth McLeod, A.M., M.D., F. R. C.S.E., Surgeon-Major, Indian Medical Service, Professor of Surgery in Calcutta Medical College. Svo, with Illustrations, 12s. 6d. Surgical Pathology and Morbid Anatomy (Student's Guide). By An- thony A. BowLBY, F.R.C.S., Surgical Registrar and Demonstrator of Surgical Pathology to St. Bartholomew's Hospital. Fcap. Svo, with 135 Engravings, 9s. A Course of Operative Surgery. By Christopher Heath, Surgeon to University College Hospital. Second Edition. With 20 coloured Plates (180 figures) from Nature, by M. LfiVEiLLfi, and several Woodcuts. Large Svo, 30s. By the same Author. The Student's Guide to Surgical Diagnosis. Second Edition. Fcap. Svo, 6s. 6d. Also. Manual of Minor Surgery and Bandaging. For the use of House- Surgeons, Dressers, and Junior Practi- tioners. Eighth Edition. Fcap. Svo, with 142 Engravings, 6s. Also. Injuries and Diseases of the Jaws. Third Edition. Svo, with Plate- and 206 Wood Engravings, 14 s. J. 8f A. CHURCHILDS RECENT WORKS. II The Practice of Surgery : A Manual. By Thomas Bryant, Surgeon to Guy's Hospital. Fourth Edition. 2 vols, crown 8vo, with 750 Engravings (many being coloured), and including 6 chromo plates, 32s. Surgery : its Theory and Prac- tice (Student's Guide). By William J. Walsham, F.R.C.S., Assistant Surgeon to St. Bartholomew's Hospital. Fcap. 8vo, with 236 Engravings, los. 6d. The Surgeon's Vade-Mecum : A Manual of Modern Surgery. By R. Druitt, F.R.C.S. Twelfth Edition. By Stanley Boyd, M.B., F.R.C.S. Assistant Surgeon and Pathologist to Charing Cross Hospital. Crown 8vo, with 373 Engravings i6s. Regional Surgery : Including Surgical Diagnosis. A Manual for the use of Students. By F. A. SouTHAM, M.A., M.B., F.R.C.S., As- sistant Surgeon to the Manchester Royal Infirmary. Part I. The Head and Neck. Crown 8vo, 6s. 6d. — Part II. The Upper Extremity and Thorax. Crown 8vo, 7s. 6d. Part III. The Abdomen and Lower Extremity. Crown 8vo, 7s. Illustrations of Clinical Surgery. By Jonathan Hutchinson, F.R.S., Senior Surgeon to the London Hospital. In occasional fasciculi. I. to XIX., 6s. 6d. each. Fasciculi I. to X. bound, with Appendix and Index, £■}, iQs. By the same Author. Pedigree of Disease : Being Six Lectures on Temperament, Idiosyncrasy, and Diathesis. 8vo, 5s. Treatment of Wounds and Frac- tures. Clinical Lectures. By Sampson Gamgee, F.R.S.E., Surgeon to the Queen's Hospital, Birmingham. Second Edition. 8vo, with 40 Engravings, los. Electricity and its Manner of "Working in the Treatment of Disease. By \Vm. E. Steavenson, M.D., Physician and Electrician to St. Bartholomew's Hospital. 8vo, 4s. 6d. Lectures on Orthopaedic Sur- gery. By Bernard E. Brodhurst, F.R.C.S., Surgeon to the Royal Ortho- pedic Hospital. Second Edition. 8vo, with Engravings, 12s. 6d. By the same Author. On Anchylosis, and the Treat- nnent for the Removal of De- formity and the Restoration of Mobility in Various Joints. Fourth Edition. 8vo, with Engravings, 5s. Also. Curvatures and Diseases of the Spine. Third Edition. 8vo, with Engravings, 6s. Diseases of Bones and Joints. By Charles Macnamara, F.R.C.S.,. Surgeon to, and Lecturer on Surgery at, the Westminster Hospital. 8vo, with Plates and Engravings, 12s. Injuries of the Spine and Spinal Cord, and NERVOUS SHOCK, in their Surgical and Medico- Legal Aspects. By Herbert W. Page, M.C. Cantab., F.R.C.S., Surgeon to St. Mary's- Hospital. Second Edition, post 8vo, lOs. Face and Foot Deformities. By Frederick Churchill, CM., Sur- geon to the Victoria Hospital for Children. 8vo, with Plates and Illustrations, los. 6d. Clubfoot : Its Causes, Pathology, and Treatment. By Wm. Adams, F.R.C.S., Surgeon ta the Great Northern Hospital. Second Edition. 8vo, with 106 Engravings and 6 Lithographic Plates, 15s. By the same Author. On Contraction of the Fingers, and its Treatment by Subcutaneous Opera- tion ; and on Obliteration of Depressed Cicatrices, by the same Method. 8vo, with 30 Engravings, 4s. 6d. Also. Lateral and other Forms of Curvature of the Spine : Their Pathology and Treatment. Second Edi- tion. 8vo, with 5 Lithographic Plates and 72 Wood Engravings, ids. 6d. Spinal Curvatures : Treatment by Extension and Jacket ; with Remarks on some Affections of the Hip, Knee, and Ankle-joints. By PI. Mac- naughton Jones, M.D., P\R.C.S. I, and Edin. Post 8vo, with 63 Engravings, 4s. 6d. On Diseases and Injuries of the Eye : A Course of Systematic and Clinical Lectures to Students and Medical Practitioners. By J. R. Wolfe, M.D., F.R.C.S.E., Lecttirer on Ophthalmic Medicine and Surgery in Anderson's Col- lege, Glasgow. With 10 Coloured Plates and 157 Wood Engravings. 8vo, £1 Is. Hints on Ophthalmic Out-Patient Practice. By Charles Higgens, Ophthalmic Surgeon to Guy's Hospital. Third Edition. Fcap. 8vo, 3s. Short Sight, Long Sight, and Astigmatism. By George F. Helm, M.A., M.D., F.R.C.S., formerly Demon- strator of Anatomy in the Cambridge Medical School. Crown 8vo, with 35 Engravings, 3s. 6d. Manual of the Diseases of the Eye. By Charles Macnamara, F.R.C.S., Surgeon to Westminster Hos- pital. Fourth Edition. Crown 8vo, with 4 Coloured Plates and 66 Engravings, lOs. 6d. 12 J. ^- A. CHURCHILL'S RECENT WORKS. The Student's Guide to Diseases of the Eye. ByEdwardNettleship, F.R.C.S., Ophthalmic Surgeon to St. Thomas's Hospital. Fourth Edition. Fcap. 8vo, with 164 Engravings and a Set of Coloured Papers illustrating Colour- Blindness, 7s. 6d. Normal and Pathological His- tology of the Human Eye and Eyelids. By C. Fred. Pollock, M.D., F.R.C.S. and F.R.S.E., .Surgeon for Diseases of the Eye to Anderson's College Dispensary, Glasgow. Crown 8vo, with 100 Plates (230 drawings), 15s. Atlas of Ophthalmoscopy. Composed of 12 Chromo - lithographic Plates (59 Figures drawn from nature) and Explanatory Text. By Richard LiEBRElCH, M.R.C.S. Translated by H. Rosborough Swanzy, M.B. Third edition, 4to, 40s. Glaucoma : Its Causes, Symptoms, Pathology, and Treatment. By Priestley Smith, M.R.C.S., Ophthalmic Surgeon to the Queen's Hospital, Birmingham. 8vo, with Lithographic Plates, ids. 6d. Refraction of the Eye : A Manual for Students. By GusTAVUS Hartridge, F.R.C.S., Assistant Physi- cian to the Royal Westminster Ophthalmic Plospital. Second Edition. Crown 8vo, with Lithographic Plate and 94 Woodcuts, 5s. 6d. Squint : (Clinical Investigations on). By C. Schweigger, M.D., Professor of Oph- thalmology in the University of Berlin. Edited by Gustavus Hartridge, F.R.C.S. 8vo, 5s. The Electro-Magnet, And its Employment in Ophthalmic Sur- gery. By Simeon Snell, Ophthalmic Surgeon to the .Sheffield General In- firmary, &c. Crown 8vo, 3s. 6d. Practitioner's Handbook of Diseases of the Ear and Naso- pharynx. By H. Macnaughton Jones, M.D., late Professor of the Queen s University in Ireland, Surgeon to the Cork Ophthalmic and Aural Hospital. Third Edition of "Aural .Surgery." Roy. 8vo, with 128 Engravings, 6s. By the same Author. Atlas of Diseases of the Mem- hrana Tympani, In Coloured Plates, containing 62 Figures, with Text. Crown 4to, 21s. Endemic Goitre or Thyreocele : Its Etiology, Clinical Characters, Patho- logy, Distribution, Relations to Cretinism, Myxoedema, &c., and Treatment. By William Robinson, M.D. 8vo, 5s. Diseases and Injuries of the Ear. By Sir William B. Dalby, Aural Surgeon to St. George's Hospital. Third Edition. Crown 8vo, with Engravings, 7s. 6d. By the Same Author, Short Contributions to Aural Surgery, betw^een 1875 and 1886. 8vo, with Engravings, 3s. 6d. Diseases of the Throat and Nose : A Manual. By Sir MoRELL Mackenzie, M.D., Senior Physician to the Hospital for Diseases of the Throat. Vol. II. Diseases of the Nose and Naso- pharynx ; with a .Section on Diseases of the CEsophagus. Post 8vo, with 93 En- gravings, I2S. 6d. By the same Author. Diphtheria : Its Nature and Treatment, Varieties, and Local Expressions. 8vo, 5s. Sore Throat : Its Nature, Varieties, and Treatment. By Prosser James, M.D., Physician to the Hospital for Diseases of the Throat. Fifth Edition. Post 8vo, with Coloured Plates and Engravings, 6s. 6d. A Treatise on Vocal Physio- logy and Hygiene. By Gordon Holmes, M.D., Physician to the Muni- cipal Throat and Ear Infirmary. Second Edition, with Engravings. Crown 8vo, 6s. 6d. A System of Dental Surgery. By Sir John Tomes, F.R.S., and C. S. Tomes, M.A., F.R.S. Third Edition. Crown 8vo, with 292 Engravings, 15s. Dental Anatomy, Human and Comparative : A Manual. By Charles vS. Tomes, M.A., F.R.S. Second Edition. Crown 8vo, with 191 Engravings, I2s. 6d. The Student's Guide to Dental Anatomy and Surgery. By Henry Sewill, M.R.C.S., L.D.S. Second Edition. Fcap. 8vo, with 78 Engravings, 5s. 6d. Notes on Dental Practice. By Henry C. Quinby, L.D.S.R. C.S.I. 8vo, with 87 Engravings, 9s. Mechanical Dentistry in Gold and Vulcanite. By F. H. Balk- will, L.D.S. R.C.S. 8vo, with 2 Litho- graphic Plates and 57 Engravings, ids. A Practical Treatise on Mecha- nical Dentistry. By Joseph Rich- ardson, M.D., D.D.S., late Emeritus Professor of Prosthetic Dentistry in the Indiana Medical College. Fourth Edition. Roy. Svo, with 458 Engravings, 2IS. J. ^- A. CHURCHILDS RECENT WORKS. 13 Principles and Practice of Den- tistry : including Anatomy, Physiology, Pathology, Therapeutics, Dental Surgery, and Mechanism. By C. A.Harris, M.D., D.D.S, Edited by F. J. S. Gorgas, A.M., M.D., D.D.S., Professor in the Dental Department of Maryland Univer- sity. Eleventh Edition. 8vo, with 750 Illustrations, 31s. 6d. A Manual of Dental Mechanics. By Oakley Coles, L.D.S.R.C.S. Second Edition. Crown 8vo, with 140 Engravings, 7s. 6d. Elements of Dental Materia Medica and Therapeutics, with Pharmacopoeia. By James Stocken, L.D.S.R.C.S., Pereira Prizeman for Materia Medica, and Thomas Gaddes, L.D.S. Eng. and Edin. Third Edition. Fcap. 8vo, 7s. 6d. Dental Medicine : A Manual of Dental Materia Medica and Therapeutics. By F. J. S. Gorgas, A.M., M.D., D.D.S., Editor of "Harris's Principles and Practice of Dentistry," Professor in the Dental Department of Maryland University. 8vo, 14s. Atlas of Skin Diseases. By Tilbury Fox, M.D., F.R.C.P. With 72 Coloured Plates. Royal 4to, half morocco, £6 6s. Diseases of the Skin : With an Analysis of 8,000 Consecutive Cases and a Formulary. By L. D. BuLK- LEY, M.D., Physician for Skin Diseases at the New York Hospital. Crown 8vo, 6s. 6d. By the same Author. Acne : its Etiology, Pathology, and Treatment : Based upon a Study of 1,500 Cases. Svo, with Engravings, lOS. On Certain Rare Diseases of the Skin. By Jonathan Hutchinson, F.R.S., Senior Surgeon to the London Hospital, and to the Hospital for Diseases of the Skin. Svo, los. 6d. Diseases of the Skin : A Practical Treatise for the Use of Students and Practitioners. By J. N. Hyde, A.M., M.D., Professor of Skin and Venereal Diseases, Rush Medical College, Chicago. Svo, with 66 Engravings, 17s. Parasites : A Treatise on the Entozoa of Man and Animals, including some Account of the Ectozoa. ByT.SrENCERCoKitOLD,M.D., F.R.S. Svo, with 85 Engravings, 15s. Manual of Animal Vaccination, preceded by Considerations on Vaccina- tion in general. By E. Warlomont, M.D., Founder of the State Vaccine Institute of Belgium. Translated and edited by Arthur J. Harries, M.D. Crown Svo, 4s. 6d. Leprosy in British Guiana. ByJOHND.HiLLis,F.R.C.S.,M.R.I.A., ISIedical Superintendent of the Leper Asylum, British Guiana. Imp. Svo, with 22 Lithographic Coloured Plates and Wood Engravings, £\ lis. 6d. Cancer of the Breast. By Thomas W. Nunn, F.R.C.S., Con- sulting Surgeon to the Middlesex Hos- pital. 4to, with 21 Coloured Plates, £2. 2s. On Cancer : Its Allies, and other Tumours; their Medi- cal and Surgical Treatment. By F. A. Purcell, M.D., M.C., Surgeon to the Cancer Hospital, Brompton. Svo, with 21 Engravings, los. 6d. Sarcoma and Carcinoma : Their Pathology, Diagnosis, and Treat- ment. By Henry T. Butlin, F.R.C.S., Assistant Surgeon to St. Bartholomew's Hospital. Svo, with 4 Plates, Ss. By the same Author. Malignant Disease of the La- rynx (Sarcoma and Carcinoma). Svo, with 5 Engravings, 5s. Also. Operative Surgery of Malignant Disease. 8vo, 14s. Cancerous Affections of the Skin. (Epithelioma and Rodent Ulcer.) By George Thin, M.D. Post Svo, with 8 Engravings, 5s. By the same Author. Pathology and Treatment of Ringworm. Svo, with 21 Engravings, 5s- Cancer of the Mouth, Tongue, and Alimentary Tract : their Pathology, Symj^toms, Diagnosis, and Treatment. By Frederic B. Jessett, P'.R.C.S., Surgeon to the Cancer Hospi- tal, Brompton. Svo, los. Clinical Notes on Cancer, Its Etiology and Treatment ; with special reference to the Heredity-Fallacy, and to the Neurofic Origin of most Cases of Alveolar Carcinoma. By Herbert L. Snow, M.D. Lond., SurgeontotheCancer Hospital, Brompton. Crown Svo, 3s. 6d. Lectures on the Surgical Dis- orders of the Urinary Organs. By Reginald Harrison, F.R.C.S., Surgeon to the Liverpool Royal Infirmary. Third Edition, with 1 17 Engravings. Svo, 12s. 6d. Hydrocele : Its several Varieties and their Treatment. By Samuel Osborn, late Surgical Registrar to St. Thomas's Hospital. Fcap. Svo, with Engravings, 3s. By the same Author. Diseases of the Testis. Fcap. Svo, with Engravings, 3s. 6d. 14 J. 8c A. CHURCHILL'S RECENT WORKS. Diseases of the Urinary Organs. Clinical Lectures. By Sir Henry Thompson, F.R.C.S., Emeritus Pro- fessor of Clinical Surgery in University College. Seventh (Students') Edition. 8vo, with 84 Engravings, 2s. 6d. By the same Author. Diseases of the Prostate : Their Pathology and Treatment. Sixth Edition. 8vo, with 39 Engravings, 6s. Also. Surgery of the Urinary Organs. Some Important Points connected there- with. Lectures delivered in the R.C..S. 8vo, with 44 Engravings. Students' Edition, 2s. 6d. Also. Practical Lithotomy and Litho- trity; or, An Inquiryinto the BestModes of Removing Stone from the Bladder. Third Edition. 8vo, with 87 Engravings, IDS. Also. The Preventive Treatment of Calculous Disease, and the Use of Solvent Remedies. Second Edition. Fcap. 8vo, 2s. 6d. Also. Tumours of the Bladder: Their Nature, Symptoms, and Surgical Treatment. 8vo, with numerous Illustra- tions, 5s. Also. Stricture of the Urethra, and Uri- naryFistulee: their Pathology and Treat- ment. Fourth Edition. With 74 Engrav- ings. 8vo, 6s. Also. The Suprapubic Operation of Opening the Bladder for the Stone and for Tumours. 8vo, with 14 Engravings, 3s. 6d. The Surgery of the Rectum. By Henry Smith, Professor of Surgery in King's College, Surgeon to the Hos- pital. Fifth Edition. 8vo, 6s. Modern Treatment of Stone in the Bladder by Litholopaxy. By P. J. Freyer, M.A., M.U., M.Ch., Bengal Medical Service. 8vo, with En- gravings, 5s. Diseases of the Testis, Sperm- atic Cord, and Scrotum. By Thomas B. Curling, F.R.S., Consult- ing Surgeon to the London Hospital. Fourth Edition. 8vo, with Engravings, i6s. Diseases of the Rectum and Anus. By W. Harrison Critps, F. R.C.S., Assistant Surgeon to St. Bar- tholomew's Hospital, &c. 8vo, with 13 Lithographic Plates and numerous Wood Engravings, 12s. 6d. Urinary and Renal Derange- ments and Calculous Disorders. By Lionel S. Beale, F.R.C.P., F.R.S., Physician to King's College Plospital. 8vo, 5s. Fistula, Haemorrhoids, Painful Ulcer, Stricture, Prolapsus, and other Diseases of the Rectum : Their Diagnosis and Treatment. By William. Allingham, Surgeon to St. Mark's Hospital for Fistula. Fourth Edition. 8vo, with Engravings, los. 6d. Pathology of the Urine. Including a Complete Guide to its Analy- sis. By J. L. W. Thudichum, M.D., F.R.C.P. Second Edition, rewritten and enlarged. 8vo, with Engravings, 15s. Student's Primer on the Urine. By J. Travis Whittaker, M.D., CHni- cal Demonstrator at the Royal Infirmary, Glasgow. With 16 Plates etched on Copper. Post 8vo, 4s. 6d. Syphilis and Pseudo-Syphilis. By Alfred Cooper, F.R.C.S., Surgeon to the Lock Hospital, to St. Mark's and the West London Hospitals. 8vo, los. 6d. Diagnosis and Treatment of Syphilis. By Tom Robinson, M.D., Physician to St. John's Hospital for Dis- eases of the Skin. Crown Svo, 3s. 6d. By the same Author. Eczema : its Etiology, Patho- logy, and Treatnnent. Crown Svo, 3s. 6d. Coulson on Diseases of the Bladder and Prostate Gland. Sixth Edition. By Walter J. Cotjlson, Surgeon to the Lock Hospital and to St. Peter's Hospital for Stone. 8vo, i6s. The Medical Adviser in Life As- surance. BySirE.H.SiEVEKiNG, M.D., F.R.C.P. Second Edition. Crown Svo, 6s. A Medical Vocabulary : An Explanation of all Terms and Phrases used in the various Departments of Medical Science and Practice, their Derivation, Meaning, Application, and Pronunciation. By R. G. Mayne, M.D., LL.D. Fifth Edition. Fcap. Svo, los. 6tl. A Dictionary of Medical Science: Containing a concise Exjjlanation of the various Subjects and Terms of Medicine, &C. By ROBLEY DUNGLISO.N, M.D., LL.D. Royal Svo, 28s. Medical Education And Practice in all parts of the World. By H. J. Hardwicke, M.D., M.R.C.P. Svo, los. INDEX. Abercrombie's Medical Jurisprudence, 4 Adams (W.) on Clubfoot, 11 on Contraction of the Fingers, 11 on Curvature of the Spine, 11 Alexander's Displacements of the Uterus, 6 Allan on Fever Nursing, 7 Outlines of Infectious Diseases, 7 Allingham on Diseases of the Rectum, 14 Anatomical Remembrancer, 3 Balfour's Diseases of the Heart and Aorta, 9 Balkwill's Mechanical Dentistry, 12 Barnes (R.) on Obstetric Operations, 5 on Diseases of Women, 5 Basil's Commoner Diseases and Accidents, 10 Beale's Microscope in Medicine, 8 Slight Ailments, 8 Urinary and Renal Derangements, 14 Bellamy's Surgical Anatomy, 3 Bennet (J. H.) on the Mediterranean, 10 on Pulmonary Consumption, 10 Bentley and Trimen's Medicinal Plants, 7 Bentley's Manual of Botany, 7 Structural Botany, 7 Systematic Botany, 7 Bowlby's Surgical Pathology and Morbid Anatomy, 10 Braune's Topographical Anatomy, 3 Brodhurst's Anchylosis, 11 ■ — — Curvatures, &c., of the Spine, 11 Orthopeedic Surgery, ii Bryant's Acute Intestinal Strangulation, 9 Practice of Surgery, 11 Bucknill and Tuke's Psychological Medicine, 3 Buist's Vaccinia and Variola, 8 Bulkley's Acne, 13 Diseases of the Skin, 13 Burdett's Cottage Hospitals, 4 Pay Hospitals, 4 Burton's Midwifery for Midwives, 6 Butlin's Malignant Disease of the Larynx, 13 Operative Surgery of Malignant Disease, 13 Sarcoma and Carcinoma, 13 Buzzard's Diseases of the Nervous System 9 Peripheral Neuritis, 9 Carpenter's Human Physiology, 4 Cayley's Typhoid Fever, 8 Charteris on Health Resorts, 10 Practice of Medicine, 8 Chavers' Diseases of India, 8 Churchill's Face and Foot Deformities, 11 Clouston's Lectures on Mental Diseases, 5 Cobbold on Parasites, 13 Coles' Dental Mechanics, i^ Cooper's Syphilis and Pseudo-Syphilis, 14 Coulson on Diseases of the Bladder, 14 Courty's Diseases of the Uterus, Ovaries, &c., 6 Cripps' Diseases of the Rectum and Anus, 14 CuUingworth's Manual of Nursing, 6 Short Manual for Monthly Nurses, 6 Curling's Diseases of the Testis, 14 Dalby's Diseases and Injuries of the Ear, 12 Day on Diseases of Children, 6 on Headaches, 10 Dobell's Lectures on Winter Cough, 8 Loss of Weight, &c., 8 Mont Dor^ Cure, 8 Domville's Manual for Nurses, 6 Doran's Gynaecological Operations, 6 Down's Mental Affections of Childhood, 5 Draper's Text Book of Medical Physics, 4 Druitt's Surgeon's Vade-Mecum, 11 Duncan on Diseases of Women, 5 on Sterility in Woman, 5 Dunglison's Medical Dictionary, 14 East's Private Treatment of the Insane, 5 Ebstein on Regimen in Gout, 9 Ellis's Diseases of Children, 6 Fagge's Principles and Practice of Medicine, Fayrer's Climate and P'evers of India, 7 Fenwick's Chronic Atrophy of the Stomach, 8 Medical Diagnosis, 8 Outlines of Medical Treatment, 8 Flint's Principles and Practice of Medicine, 7 Flower's Diagrams of the Nerves, 3 Fox's (C. B.) Examinations of Water, Air, and Food, 5 Fox's (T.) Atlas of Skin Diseases, 13 Freyer's Litholopaxy, 14 Frey's Histology and Histo-Chemistry, 4 Galabin's Diseases of Women, 6 Manual of Midwifery, 5 Gamgee's Treatment of Wounds and Fractures, 11 Godlee's Atlas of Human Anatomy, 3 Goodhart's Diseases of Children, 6 Gorgas' Dental Medicine, 13 Gowers' -Diseases of the Brain, g Diseases of the Spinal Cord, 9 Manual of Diseases of Nervous System, 9 Medical Ophthalmoscopy, 9 Pseudo-Hypertrophic Muscular Paralysis, 9 Granville on Gout, 9 on Nerve Vibration and Excitation, 9 Guy s Hospital Formulae, 2 Reports, 2 Habershon's Diseases of the Abdomen, 9 Liver, 9 , Stomach, 9 Pneumogastric Nerve, 9 Hambleton's What is Consumotion? 8 Hardwicke's Medical Education, 14 Harley on Diseases of the Liver, 9 Inflammations of the Liver, 9 Harris's Dentistry, 13 Harrison's Surgical Disorders of the Urinary Organs, 13 Hartridge's Refraction of the Eye, 12 Harvey's Manuscript Lectures, 3 Heath's Injuries and Diseases of the Jaws, 10 Minor Surgery and Bandaging, 10 Operative Surgery, 10 Practical Anatomy, 3 Surgical Diagnosis, 10 Helm on Short and Long Sight, &c., 11 Higgens' Ophthalmic Out-patient Practice, 11 Hillis' Leprosy in British Guiana, 13 Holden's Dissections, 3 Human Osteology, 3 Landmarks, 3 Holmes' (G.) Vocal Physiology and Hygiene, 12 Hood's (D. C. ) Diseases and their Commencement, 6 Hood (P.) on Gout, Rheumatism, &c., 9 Hooper's Physician's Vade-l\Iecum, 8 Hutchinson's Clinical Surgery, n Pedigree of Disease, 11 '■— Rare Diseases of the Skin, 13 Hyde's Diseases of the Skin, 13 lames (P.) on Sore Throat, 12 Jessett's Cancer of the Mouth, &c., 13 Johnson's Medical Lectures and Essays, 8 Jones (C. H.) and Sieveking's Pathological Anatomy, 4 Jones' (H. McN.) Diseases of the Ear and Pharynx, 12 — — Atlas of Diseases of Membrana Tympani, 12 Spinal Curvatures. 11 Journal of British Dental Association, 2 ■ ■ Mental Science, 2 King's Manual of Obstetrics, 5 Lancereaux's Atlas of Pathological Anatomy, 4 Lewis (Bevan) on the Human Brain, 4 Liebreich's Atlas of Ophthalmoscopy, 12 Liveing's Megrim, Sick Headache, &c., 9 London Hospital Reports, 2 Lfickes' Hospital Sisters and their Duties, 7 Macdonald's (J. D.) Examination of Water and Air, 4 Mackenzie on Diphtheria, 12 on Diseases of the Throat and Nose, 12 McLeod's Operative Surgery, 10 MacMunn's Spectroscope in Medicine, 8 IMacnamara's Diseases of the Eye, 11 Bones and Joints, 11 Marcet's Southern and Swiss Health-Resorts, 10 Martin's Ambulance Lectures, 10 Mayne's Medical Vocabulary, 14 Middlesex Hospital Reports, 2 Mitchell's Diseases of the Nervous System, 9 Moore's Family Medicine for India, 7 Health-Resorts for Tropical Invalids, 7 — ^ Manual of the Diseases of India, 7 Morris' (H.) Anatomy of the Joints, 3 Morton's Spina Bifida, 10 Mouat and Snell on Hospitals, 4 Nettleship's Diseases of the Eye, 12 Nunn's Cancer of the Breast, 13 Ogston's Medical Jurisprudence, 4 Ophthalmic (Royal London) Hospital Reports, 2 Ophthalmological Society's Transactions, 2 Oppert's Hospitals, Infirmaries, Dispensaries, &c. , 4 Osborn on Diseases of the Testis, 13 on Hydrocele, 13 Owen's Materia Medica, 7 Page's Injuries of the Spine, 11 Parkes' Practical Hygiene, 5 Pavy on Diabetes, 10 Pavy on Food and Dietetics, 10 [Continued on the next pagt. Index — contimied. Pharmaceutical Journal, 2 Pharmacopoeia of the London Hospital, 7 PhiUips' Materia Medica and Therapeutics, 7 Pollock's Histology of the Eye and Eyelids, 12 Porritt's Intra-Thoracic Effusion, 8 Purcell on Cancer, 13 Quinby's Notes on Dental Practice, 12 Raye's Ambulance Handbook, 10 Reynolds' (J. J.) Diseases of Women, 5 Notes on Midwifery, 5 Richardson's Mechanical Dentistry, 12 Roberts' (C.) Manual of Anthropometry, 5 Detection of Colour-BIindness, 5 Roberts' (D. Lloyd) Practice of Midwifery, 5 Robinson (Tom) on Eczema, 14 — — on Syphilis, 14 Robinson (W.l on Endemic Goitre or Thyreocele, 12 Ross's Aphasia, 9 Diseases of the Nervous System, 9 Handbook of ditto, 9 Routh's Infant Feeding, 7 Royal College of Surgeons Museum Catalogues, 2 Royle and Harley's Materia IMedica, 7 St. Bartholomew's Hospital Catalogue, 2 St. George's Hospital Reports, 2 St. Thomas's Hospital Reports, 2 Sansom's Valvular Disease of the Heart, 8 Savage on the Female Pelvic Organs, 5 .Schweigger on Squint, 12 Sewill's Dental Anatomy, 12 Sharkey's Spasm in Chronic Nerve Disease, 9 Shore's Elementary Practical Biologj', 4 Sieveking's Life Assurance, 14 Simon's Public Health Reports, 4 Smith's (E.) Clinical Studies, 6 ■ Diseases in Children, 6 Wasting Diseases of Infants and Children, 6 Smith's (J. Greig) Abdominal Surgery, 6 Smith's (Henry) Surgery of the Rectum, 14 Smith's (Heywood) Dysmenorrhoea, 5 Smith (Priestley) on Glaucoma, 12 Snell's Electro-Magnet in Ophthalmic Surgery, 12 Snow's Clinical Notes on Cancer, 13 Southam's Regional Surgery, 11 Squire's Companion to the Pharmacopoeia, 7 Pharmacopceias of London Hospitals, 7 Steavenson's Electricity. 11 Stills and Maisch's National Dispensatory, 7 Stocken's Dental Materia Medica and Therapeutics, 13 Sutton's General Pathology, 4 Swain's Surgical Emergencies, 10 Swayne's Obstetric Aphorisms, 6 Taylor's Medical Jurisprudence, 4 Taylor's Poisons in relation to Medical Jurisprudence, 4 Teale's Dangers to Health, 5 Thin's Cancerous Affections of the Skin, 13 — Pathology and Treatment of Ringworm, Thomas's Diseases of Women, 6 Thompson's (Sir H.) Calculous Disease, 14 Diseases of the Prostate, 14 — Diseases of theUrinarj' Organs, 14 • Lithotomy and Lithotrity, 14 Stricture of the Urethra, 14 Suprapubic Operation, 14 Surgery of the Urinary Organs, 14 Tumours of the Bladder, 14 Thorowgood on Asthma, 8 on Materia Medica and Therapeutics, 7 Thudichum's Pathology of the Urine, 14 Tibbits' Medical and Surgical Electricity,- 10 Map of Motor Points, 10 How to use a Galvanic Battery, 10 Electrical and Anatomical Demonstrations, 10 Tilt's Change of Life, b Uterine Therapeutics, 6 Tirard's Prescriber's Pharmacopoeia, 7 Tomes' (C. S.) Dental Anatomy, 12 Tomes' (J. and C. S.) Dental Surgery, 12 Tuke's Influence of the Mind upon the Body, 5 Sleep-Walking and Hypnotism, 5 Vintras on the Mineral Waters, &c., of France, 10 Virchow's Post-mortem Examinations, 4 Walsham's Surgery : its Theory and Practice, 11 Waring's Indian Bazaar Medicines, 7 Practical Therapeutics, 7 Warlomont's Animal Vaccination, 13 Warner's Guide to Medical Case-Taking, 8 Waters' (A. T. H.) Diseases of the Chest, 8 Weaver's Pulmonary Consumption, 8 Wells' (Spencer) Abdominal Tumours, 5 Ovarian and Uterine Tumours, 5 West and Duncan's Diseases of Women, 5 West's (S.) How to Examine the Chest, 8 Whittaker's Primer on the Urine, 14 Wilks' Diseases of the Nervous System, 8 Williams' (Roger) Influence ot Sex, 4 Wilson's (.Sir E.) Anatomists' Vade-!Mecum, 3 Wilson's (G.) Handbook of Hygiene, 5 Healthy Life and Dwellings, 5 Wilson's (W. S.) Ocean as a Health-Resort, 10 Wolfe's Diseases and Injuries of the Eye, 11 Year Book of Pharmacy, 2 Yeo's (G. F.) Manual of Physiology, 4 Yeo's (J. B.) Contagiousness of Pulmonary Consump.^ tlon, 8 The following CATALOGUES issued by J. & A. Churchill will be forwarded post free on application : — A. J. l\'- a. ChiirchilPs General List of about 650 works on A7iatomy^ Physiology^ Hygie7te, I\Jidzuifery^ Materia Medica, Medicine, Surgery, Chemistry, Botany, Hfc, i^^-c, with a complete Index to their Subjects, for easy reference. N.B.— jy^V List iiicludes B, C, & D. B. Selection from J. Sf A. ChurchilPs General List, comprising all recent Works published by them on the Art and Science of Medicine. C. J. 8f A. ChurchilPs Catalogue of Text Boohs specially arranged for Students. D. A selected and descriptive List of J. S,' A. ChurchilPs Works art Chemistry, Materia Medica, Pharmacy, Botany, Photography, Zoology, f he- Microscope, and other branches of Science. E. The Half-yearly List of New Works and New Editions published by J. 8f A. Churchill during the previous six months, together tvith particulars of the Periodicals issued from their House. [Sent in January and July of each year to every Medical Practitioner in the United Kingdom whose name and address can be ascertained. A large number are also sent to the United States of America, Continental Europe, India, and the- Colonies.] America. — J. ^ A. CluivcJiUl being in constant coninninication %vith various publishing- Jwnses in Boston, Nezu York, and Philadelphia, are able, notzvithstanding the absence of international copyright, to conduct negotiations favo7ii'able to English A tithors. LONDON: 11, NEW BURLINGTON STREET. Pardon <t ."ians, Printers,} [IFine Office Court, Fleet Street, E.C. University of California SOUTHERN REGIONAL LIBRARY FACILITY 305 De Neve Drive - Parking Lot 17 • Box 951388 LOS ANGELES, CALIFORNIA 90095-1388 Return this material to the library from which it was borrowed.