232 



J. W. GROVES ON SECTIONS OF ANIMAL TISSUES. 



from the lower animals. Though these may differ in some more or 

 less important details, they do in the main furnish all that for ordi- 

 nary purposes we require to know of the similar structures in man. 



Decomposition rapidly sets in, sufficiently to impair if not to neu- 

 tralize the subsequent processes ; therefore, except with certain 

 morbid structures which can only be obtained from the post-mortem 

 room, all normal material, and where possible that also which is 

 morbid, should be placed in a preservative fluid, there to be hardened 

 or softened, as the case may be, either directly after the death of the 

 animal or immediately after its removal from the living body. 



Preservatives. 

 These may be divided into two classes — 1st, those which simply 

 prevent further alteration, and 2nd, those which, in addition to pre- 

 serving, at the same time cause hardening, softening, &c, as set 

 forth in the following table : — 



" Canada Balsam. 

 Glycerine. 



1. Simple Preservatives *{ 



I Goadby's Fluid. 



2. Those which 

 also harden. 



Dammar Solution. 

 Glycerine and Carbolic Acid (15*1.) 

 w Glycerine Jelly, &c. 

 Alcohol. 



Chromic Acid (1-eight per cent, soln.) 

 S'rrml "^ Bichromate of Potash (2 per cent, soln.) 

 ,, Ammonia (ditto.) 



^ Muller's Fluid, &c. 



b. Which 

 colour 

 also. 



f Picric Acid (sat. soln.) 



3. Those which also 



soften. 



4. Those which harden 



some parts and sof- 

 ten others at the 

 same time. 



Osmic Acid (1-2 p.c. soln.) 

 *4 Gold Chloride (i p.c. soln.) 

 Alcohol and Carmine, &c. 

 L Chromic Acid (1 -eighth p.c. soln.) and 

 subsequent immersion in glycerine. 

 (For Mineral Salts — Acicls. 

 | „ Animal Matters — Alkalis. 



} 



Chromic Acid Solution and Nitric Acid. 



In the preceding table are enumerated the more ordinary and useful 

 preservatives, each of which will be presently noticed separately ; 

 though, firstly, I wish to draw your attention to three facts in 

 connection with them, which are of the greatest importance, and 

 to the want of a due regard to which may be ascribed a second cause 



