112 THE AMERICAN MONTHLY [Apr 
of the Franklin Institute, Philadelphia, proposes to hold 
the photographic exhibition early in 1902, and lasting 
about three weeks. Photo-micrography and Micropho- 
tography are included. Further particulars from F. M. 
Sawyer, Secretary of the Committee. 
PARASITES OF MAN.—Through the kindness of Professor 
Henry Kraemer of the Philadelphia College of Pharmacy, 
who loans the cuts we are able to present the paper of Dr. 
L. Napoleon Boston, the Bacteriologist to the Philadel- 
phia Hospital and Demonstrator in the Medico-Chirurgi- 
cal College, which paper was read in the Philadelphia Col- 
lege of Pharmacy, April 16, 1901. In connection there- 
with, he exhibited slides of these parasites of different 
stages of development. Those who discussed the paper 
commended its practical importance, Professor Kraemer 
secured the paper for publication in the American Jour- 
nal of Pharmacy and made the photo-engravings from 
the slides. 
MICROSCOPICAL MANIPULATION. 
DETECTING HuMAN BLoop.—A new and seemingly im- 
portant plan has been brought out by M.S. Cotton in Bull. 
Soc. Chimigquede Paris. Blood will liberate oxygen from 
hydrogen peroxide. Using 1 c.c. of blood with 250c.c. of 
hy. per., he obtained for man, 580 to 610c.c. O., for horse 
and pig, from 320 to 350 c.c.; for ox, 165 to 170; for guinea 
pig, 115 to 125; and, for sheep, from 60 to 65 ¢.c. This 
large excess in man over all the lower species would seem 
to be of diagnostic value. 
Microscopical Examination of Substances in Small Quan- 
tities. Professor Kraemer has found by experiment, dif - 
ficulties in the work which prevented uniform crystalliz- 
ing of the same substances. With solutions of alum in 
watch crystals, the crystals separate in 3 or 4 different 
forms apparently of the same system, though possibly of _ 
