NOTES ON MICRO-ORGANISMS. 27 
Two aerobian Saccharomyces forms. 
Various common moulds, including Dematium pullulans. 
Altogether a very fair array. 
Some interesting figures relative to organisms in the air are 
given by Miquel from observations made at Montsouris. In a 
cubic metre of air he found— 
In thesautuminy <2. s-see.- 142 organisms. 
sy WEDECR oc «<5 2.5 a saccotere 49 = 
SMS PCIE one vn va nasi ede is 
PEPEMEMINIEL ans sescsdees 105 5 
No Bacteria were found at from 2,000 to 4,000 feet above sea 
level. 
In a cubic metre of air in the Rue de Rivoli, Paris, he found 
5,500 organisms. 
A good deal of matter has of late appeared in print in connec- 
tion with the organisms present in potable waters, and methods 
have been described based on Dr. Koch’s gelatine process for 
their estimation and identification. Dr. Percy Frankland, in a 
paper read before the Society of Chemical Industry, described 
such a process in detail, and also appended some interesting 
experiments on filtration through different substances, such as 
sand, animal and wood charcoal, spongy iron, brickdust, coke, 
etc., from which it appears that after some weeks’ use animal 
charcoal proved the least effective, the number of organisms after 
filtration being much greater than before, whilst spongy iron and 
coke gave a reduction of 99°8 per cent. and 98°5 per cent. re- 
spectively. Powdered coke is very easily obtained and adapted 
for use by washing well in boiling water till soluble matters are 
removed. With a large and a small glazed flower-pot, a cork, and 
a piece of glass tube an efficient filter can be fitted up at a 
nominal cost. Such an instrument would be economical for a 
working man, and possesses one or two distinct advantages, viz., 
one can see to a certain extent what is going on and keep a watch 
on the cleanliness of the upper layer of coke, and, again, fresh 
