248 THE AMERICAN MONTHLY [Sed 
stain. The latter stain is so difficult to prepare it is best 
to buy it already prepared and tested. 
For ordinary work in examining blood the following 
stains and methods of work are perhaps as convenient, 
simple and efficient as any other. Prepare the solutions 
as follows: 
A. A saturated alcoholic solution of methylene blue, 
and keep. as a stock solution. 
B. Stock solution A lcc. aqua distillat 9 cc. This is 
an ordinary counter stain for blood and pus, but the next 
solution meets almost every need, so that B may be dis- 
pensed with. . 
C. Loeffler’s M. B. solution: Stock solution A. 30 cc. 
1-10,000 solution of KoH.100 cc. This is the stain to use 
for the diptheria bacillus, but it is as good as any other 
preparation to use for a counter stain. The weak aque- 
ous solutions of M.B. deteriorate and need to be frequent- 
ly renewed. 
D. Eosin 0.5 grm. 175 per cent alcohol 100 ce. 
EH. Ehrlich’s tri-acid stain, which is purchased already 
prepared. 
To stain with Hosin and methylene blue: 3 
1. Clean and polish two cover glasses and a slide with 
alcohol and a towel. 
2. Puncture to draw blood. Touch one cover slip 
lightly to the drop, and place it upon the other cover 
slip so that the blood spreads between their surfaces. 
After blood has spread, catch these glasses by their edges 
and draw them quickly and smoothly apart so that each 
glass shall be covered with a blood film or ‘‘smear.” 
3. Dry these specimens in the air or by holding them 
near a flame where the hand can endure the heat. If the 
specimen dries too slowly, crenated corpuscles are apt to 
result. 
4. Fix the film either by heat or in some solution. 
