ON SOME PROTEIN CRYSTALLOIDS 85 



To a boiling 0.75 per cent common sait solution, sublimate is added 

 to saturation (12 grm. for 100 ce). The solution is then allowed to cool, 

 when crystals of sublimate make their appearance. Préserve the solution 

 without decanting (M. Heidenhain). 



Martin Heidenhain's HgCb solution — 100 ce. 

 Picricacid 1 grm. 



Tannic acid — 1 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 Paraffin, and sériai sections eut not thicker than 2 — 3 p. Sections of this 

 thinness permit the exact position and the détails 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 (1) and fixed to the slide by Mann' s albumen method (2) and then 

 stained in Mann's Methylblau-Eosine mixture as follows : 



Requisites. 



The staining fluid. 



a. 1 per cent methylblau in Aq. dist. — 35 ce. 

 1 per cent watersoluble eosin in Aq. dist. — 45 ce. 

 Aq. dist. — 100 ce. 



b. 1 per cent NaOH solution in Aie. absol. 



The Methylwasserblau (C37 H26 N3 S3 O9 Na3) was obtained from 

 D r Grubler, Leipzig. 



Method : 



1. Stain for 24 hours. 



2. Rinse the dark blue sections in ordinary water. 



3. Dehydrate thoroughly with absolute alcohol. 



(1) Gulland : Journ. of Anat. and Physiol., 1891, p. 56. 



(2) Mann : A new fixing fluid for animal tissues; Anat. Anz.. Jahrg. VIII, 1893, N° I2-I3, 

 p. 442, and Journ. Scottish Microsc. Soc, 1S94, p. 161. 



