G. Carl Huber 
©) 
we) 
Oo 
filtered through flannel or muslin. Injection may be made by means of an 
ordinary syringe; it is only necessary to fill the cannula with acetone. The 
tissue or organ is placed into hydrochloric acid 12 to 24 hours after the in- 
jection and is removed from the acid after two or three days and washed in 
flowing water. The pigments suggested by Krassuskaja are not soluble in 
acetone and are, therefore, only held in suspension. The mass did not seem 
to me suitable for injecting capillaries and other exceedingly fine tubular 
structures. This led to a modification of it and the mass now used in this 
laboratory is as follows: 
To obtain a stock solution, 30 grms. of photoxylin are dissolved in 550 ec. 
of acetone, which requires about 24 hours. Twenty grms. of camphor are 
dissolved in 50 cc. of acetone. The two solutions are then thoroughly mixed 
Fie. 1. Injection apparatus: A, pipe carrying water to tank; B, conveying 
water from tank and connected with waste-pipe. For further details see text 
(page 394). 
in a bottle with a well-fitting glass stopper. This stock solution may be kept 
for a long time. After experimenting for a long time, it was found that 
Alkanin* answered very well for the purpose of a red color. It is readily 
soluble in acetone, is not washed out of the preparation with water, alcohol, 
or xylol, and is not decolored in the hydrochloric acid. It is the only sub- 
stance soluble in acetone and meeting the other requirements which I have 
thus far been able to find. The preparation of alkanin first used was one 
that had been in the laboratory a long time and had become hard and brittle. 
The alkanin, as obtained from Gruebler, is in the form of a thick paste. 
Later observations have shown that the dried form answers the purpose 
better than a fresher preparation. The injection mass now used is made by 
*Fettlosliches Roth, Gruebler, also written Alcanin. 
