46 THE MICROSCOPE. March 
These being hung inside a funnel form a corrugated filter 
support whichis unaffected by liquids likely to be filtered 
through a glass funnel, and can be thoroughly cleansed 
with a minimum of labor. 
The Medical Inspection of Schools._The Health de- 
partment of New York City has become convinced that 
one of the greatest sources of the spread of contagious and 
infectious diseases among children is through contact 
with each other in the schools, and has asked for an appro- 
priation for a medical inspector in all the schools in the 
city, public, private and parochial. 
There are certain practices which now exist, such as 
drinking from the same cup and using the same towel, 
which should be prohibited. It is strange that any intelli- 
gent educator should allow such practices. Another thing 
which otherwise good instructors do, is to allow their 
pupils to sit in close unventilated rooms. It has been 
proven by experiment that scholars of moderate ability 
who use class-rooms well ventilated will at the end of the 
term surpass much brighter scholars who have been kept 
in unventilated rooms. 
Counting Blood Corpuscles.—Dr. Judson Deland, of 
Philadelphia has invented an instrument for counting 
blood corpuscle. It works on the centrifugal force prin- 
cipal, and accomplishes the measurement by means of 
comparative bulks. A quantity of blood is placed ina 
finely graduated tube and the latter revolved at a speed of 
about 1,000 revolutionsa minute. The corpuscles divide 
by force of gravity, and form on the side of the tube in 
easily traceable divisions of red corpuscles, white corpus- 
cles, and serum. ‘The new method permits of larger, and 
consequently more representative quantitatives being 
used in experimenting, besides doing away with actual 
microscopic counting. 
Pimply Potatoes.—A peculiar condition of potatotubers 
commonly known as ‘‘pimply”’’ potatoes has been for some 
years past a quite serious drawback to the potato industry 
in some sections of the State. The cause of these pecu- 
