ON SOME PROTEIN CRYSTALLOIDS. 115 



To a boiling 07 5 per cent, common salt solution, sublimate is 

 added to saturation (12 grm. for 100 cc). 'Hie solution is then 

 allowed to cool, when crystals of sublimate make their appearance. 

 Preserve the solution without decanting (M. Heidenhain). 



Martin Heidenhain's corrosive sublimate solution, 100 cc. : — 

 Picric Acid ... ... ... i grm. 



Tannic Acid ... ... ... i grm. 



(The Tannic Acid may be omitted if preferred.) 

 Material fixed in absolute Alcohol gives, however, poor results 

 with the stain I employed, and requires very great care in the 

 decolourising process. The picro-corrosive alcohol gives much 

 better results, but the material which stained most successfully 

 was fixed by the watery picro-corrosive. 



The tissues were carefully dehydrated, and taken through 

 Chloroform into Parafiin, and serial sections cut not thicker than 

 2 — 3 A*. Sections of this thinness permit the exact position and 

 the details of the conglomerate crystalloids to be determined with 

 the greatest facility. 



The paraffin sections were spread out on warm water (40 — 45^ 

 C), after Gulland,* and fixed to the slide by Mann's albumen 

 method,! and then stained in Mann's Methylblau-Eosine mixture 

 as follows : — 



Reqiiisites : — The Staining Fluid. 

 a. — I per cent, methylblau in distilled water ... 35 cc. 

 I per cent, water-soluble eosin in distilled 



water ... ... ... 45 cc. 



Distilled water ... ... ... 100 cc. 



b. — I per cent, caustic soda solution in absolute alcohol. 

 The Methylwasserblau (C37 H26 N3 S3 O9 Na3) was 

 obtained from Dr. Griibler, Leipzig. 

 Method : — 



I. — Stain for twenty-four hours. 

 2. — Rinse the dark blue sections in ordinary water. 

 3. — Dehydrate thoroughly with absolute alcohol. 



* Gulland, ybwrw. of Anat. and Physiol., 1891, p. 56. 



t Mann, "A New Fixing Fluid for Animal Tissues," Anat. Am., Jahrg. 

 viii., 1893, Nos. 12—13, P- 442, dXiAJourn. Scottish Micro. Soc, 1894, p. 161. 



