[ 869 ] 



Some Ibarbening Hgcnte : 



Zbciv Special {properties an^ /in)etbo^5 of lllsnuj.'' 



By Prof. V. A. Latham, D.D.S., F.R.M.S., 



Ih charge of the Microscopical Laboratories of the North- Western 



University ; Women s Medical School; Curator of the Museum : 



Professor of Histology, Pathology, and Bacteriology, 



American College of Dental Surgery ; 



Late Assistant i?i Pathology, etc., Uiiiversity of Michigati. 



THE most essential point in Microscopic Investigation is the 

 proper hardening of the material to be examined ; and this 

 must be done gradually, for if any tissue is placed in a 

 strong solution, the elements of which it is composed shrink at 

 once and it is impossible to form a correct idea of their nature. 



It is quite as important that pathological specimens should be 

 as thoroughly hardened as normal tissues, but how seldom is this 

 done ! 



In the first place, it is difficult to get the morbid tissues fresh 

 enough, and yet they are often put on one side, or at most placed 

 in the lump in a small quantity of methylated spirit and water, 

 and it is expected that good sections can then be prepared from 

 them. Nothing is more erroneous than this idea. The subject 

 has probably been dead twenty-four hours at the least when the 

 autopsy is made, or perhaps longer, and, in summer especially, 

 this means utter ruin to such organs as the spleen. How import- 

 ant is it, therefore, that such organs should be put in the hardening 

 medium whilst as fresh as possible. 



For this purpose jars of proper size, and with the necessary 

 fluid, should be taken to every post-mortem examination, and bits 

 of any organ that may on any account seem interesting should be 

 put into it. Tie a small label on the various pieces, and they can 

 be separated afterwards. For labels 1 prefer to use small pieces 

 of tin with numbers punched on them, and a hole in, to tie to 

 each specimen, and number in a book to correspond with them. 

 The specimens may with advantage be allowed to remain in 

 Miiller's fluid for a week ; they are then cut into small pieces and 



* Read before the Illinois State Microscopical Society. 



International Journal of Microscopy and Natural Science. 



Third Series. Vol. III. bb 



