Wane, 
é = 
sc aes 
TLLusTRAT 
Vou. IV. ANN ARBOR, NOVEMBER, 1884. INO. AT: 
WHOLE No. 28. 
& 
tists, 
A BEAUTIFUL SLIDE. 
VERY beautiful polariscope slide may be made as follows: 
Heat a slide until it will melt a small portion of a menthol 
pencil as it is drawn evenly back and forth over a perfectly 
clean surface. Do not use more heat than necessary to melt 
the material evenly. Then,as it commences to crystallize, ar- 
rest its progress frequently by passing the slide quickly over 
the flame of your spirit lamp; soon the crystallization will be 
completed, a little at a time, and a very desirable slide will be 
the result. Bs H.G. 
IDENTIFICATION OF BLOOD CORPUSCLES. 
M. D. EWELL. M. D., EVANSTON, ILL. 
HE gentlemen who from time to time favor your readers 
with communications respecting the identification of blood 
corpuscles, a subject of great interest, would, as it seems to me, 
render their observations of more scientific value if they would 
