188 BACTERIOLOGY. 
set about one or one and a half feet apart in the chamber. 
A chamber having a capacity of 200 to 250 cubic feet 
would thus afford accommodation for about one hundred 
books at a time. 
Books, with the exception of their surfaces, cannot 
be satisfactorily disinfected by formaldehyde gas in the 
book-cases of houses and libraries, or anywhere except 
in special chambers constructed for the purpose, because 
the conditions required for their thorough disinfection 
cannot otherwise be complied with. 
The bindings, illustrations, and print of books are in 
no way affected by the action of formaldehyde gas. 
4. Disinfection of Carriages, Etc. 
Carriages, ambulances, cars, etc., can be easily disin- 
fected by having built a small, tight building, in which 
they are enclosed and surrounded with formaldehyde 
gas. Such a building is used for disinfecting ambu- 
lances in New York City. With the apparatus there 
employed a large amount of formalin is rapidly vapor- 
ized, and superficial disinfection is completed in thirty 
minutes. 
5. Advantages of Formaldehyde Gas over Sulphur Dioxide 
for the Disinfection of Dwellings. 
Formaldehyde gas is superior to sulphur dioxide as 
a disinfectant for dwellings, first, because it is more 
efficient in its action; second, because it is less inju- 
rious in its effects on household goods; third, because 
when necessary it can easily be supplied from a gen- 
erator placed outside of the room and watched by an 
attendant, thus avoiding in some cases danger of fire. 
Apart from the cost of the apparatus and the greater 
