2l8 



NA TURE 



[July 5, 1894 



laboratories which form an integral part of many 

 industrial establishments on the continent. 



Further, here at last we have from one who is both a 

 practical man of affairs and a successful student of 

 science, a distinct endowment of research such as was 

 advocated now many years ago to deaf ears. 



We believe that Dr. Mond's noble endowment, for 

 which all true lovers of science must thank him, will 

 have far-reaching effects. 



THE HISTOLOGICAL INVESTIGATION OF 

 DISEASE. 

 Methods of PiUhplogical Histology. By C. von Kahlden. 

 Translated and edited by H. Morley Fletcher, M.D. 

 With an introduction by G. Sims Woodhead, M.D. 

 (London: Macmillan, 1894.) 



HISTOLOGIC.A.L methods have become so perfected 

 during recent years that sve are apt to forget that 

 there was an age of discovery when microtomes, special 

 dyes, celloidin and paraffin were unknown. In the days 

 of Max Schultze, of Schwann and \'irchow, tissues were 

 cut free-hand with an ordinary razor ; for the purpose of 

 embedding, pieces of carrot and liver were used, and 

 stains were not dreamt of. Solutions of salt, acetic and 

 mineral acids and iodine were the only reagents employed, 

 and gradually carmine came in use. Yet that age 

 turned out its heroes in such men as von Biier, Remak, 

 Schwann, Max Schultze, Johannes Miiller and Virchow, 

 who with tools and media which we are unable to use 

 now, observed appearances and processes which have 

 remained the corner-stone; of normal and morbid 

 histology. We are apt to forget their deeds as being 

 antiquited. Gradually stains were introduced, and these 

 led to fresh discoveries. Dr. Klein's work on histology, 

 bejtun in .Strieker's laboratory, is a permanent testimony 

 of what a practised hand can do without our modern 

 microtomes, embedding methods, and multitude of stains. 

 H.x-matoxyline and carmine were the only dyes used. 

 Since then various kinds of microtomes, simple and 

 complicated, have been designed, and every laboratory 

 possesses apparatus for cutting in paraflin, celloidin or 

 ice, and instead of two simple stains, almost numberless 

 reagents are a necessity for the modern worker. 



On reading Dr. Morley Fletcher's edition of von 

 K.ihlcien'sbookon" Methodiof Pathological Histology," 

 we cannot help being struck with the great strides made 

 in histological technique. While fully acknowledging 

 the brilliant work of our predecessors, and even re- 

 gretting that the simpler methods of examination of 

 unstained tissue; have practically been forgotten, we feel 

 that every histologist, hnwevcr modest, should in.ikc 

 himself acquainted with the ars tcchnica of microtomy. 

 With simple methods it is possible only to study simple 

 processes, and these often with difficulty. The minute 

 s ructurc of the nervous tissues in health or disease, the 

 pithotogical changes of the blood or of infective lesions, 

 c*n only be approached, if the necessary staining 

 methods have b^en fully mastered. Stains are chemical 

 reagents, and their action must be properly appreciated. 

 There exists in our midst a large number of " hislologists '' 

 who have accustomed themselves to one stain, and what- 

 ever comes into their hands is treated in the same manner> 

 NO. I 288. VOL. 50] 



and they even acknowledge their inability of recognising 

 tissues or lesions stained in any other way. Carmine 

 specimens often trouble those who have become the 

 slaves of hicmatoxyline. We cannot sympathise with 

 them ; their methods are at fault, and they have not 

 appreciated the value and raison d'etre of staining. 

 Many great and important discoveries have been made 

 by morbid histologists such as Weigert, Ehrlich, and 

 others, by methods which at first sight appear to be 

 empirical, but are based on sound chemical principles, 

 discoveries which have proved as useful to the physi- 

 ologist and anatomist as to the pathologist. It is von 

 Kahlden's merit to have collected the most important 

 histological methods, previously scattered and hidden 

 away in archives and journals, and thus to have made 

 them more accessible ; and we are indebted to Dr. 

 Morley Fletcher for having given us a readable English 

 translation of a work which rightly enjoys great 

 popularity abroad. 



The few critical remarks which we shall m.\ke apply 

 chiefly to the German original. The methods of 

 embedding in paraffin and celloidin, and of preparing 

 sections by means of freezing, are well described, and if 

 to some the hints given appear incomplete, it should 

 be remembered that as the work is meant to be a guide 

 for the pathologist, some knowledge of histological 

 methods may reasonably be assumed to exist. The 

 Cambridge rocking microtome was deserving of more 

 than a short reference, at least in an English edition, for 

 ; with us paraflin is much more en vogue for delicate work 

 than celloidin. A few notes might have been added 

 stating for what tissues and stains each embedding 

 method should be used, for the inexperienced have 

 generally difficulties in deciding how to proceed with 

 tissues supplied to them for ex.imination. For the 

 staining of bacteria in tissues, for instance, the paraffin 

 method is the only satisfactory one. The " metal lifter" is 

 a piece of rough apparatus we object to, and recommend 

 a strip of cigarette paper as being the most delicate 

 carrier for transferring sections from water or clearing 

 medium to the slide. Under "double staining' no allusion 

 is made to acid fuchsine, a most selective and beautiful 

 stain. We have little to add to the section on bacterial 

 staining, but venture to offer an important suggestion. 

 When examining for bacteria in albuminous or gelatinous 

 media, it is advisable to remove the ground substance by 

 means of acetic acid. From personal experience we do 

 not agree that Gabbet's method is the best for the 

 detection of tubercle bacilli in sputum. Ziehl's and Van 

 Ketel's methods are far more certain. In the latter the 

 bacteria are previously trcited with carbolic acid, which 

 destroys them, so that there is no danger of disseminat- 

 ing infective matter, while at the same time the staining 

 power of the microorganisms is greatly increased. 

 Carbolic acid should be added to all microbic m.ilerial, 

 so as to avoid all possible risk of infection. Moreover, 

 treated in this manner any material may be kept 

 indefinitely for histological examination. 



The chapter on blood examination is excellent, and 

 must prove extremely useful also to the physician. The 

 systematic study of the blood at the bedside is still too 

 much neglected in this country, though in cases of 

 anitmia it is of the utmost importance, and without a 



