21 
made. The surfaces of wood and whitewash were scraped deeph" in 
making cultivations. Excluding the experiments which failed b}- 
reason of the presence of B. subtilis^ 5 per cent solution of formalin 
killed all organisms on wood and wall paper, and failed only with B. 
pyocyaneus on whitewash. With 1 per cent the only failure was with 
Streptococcus pyogenes albus on whitewash; with 2 per cent every 
surface was absolutely sterilized. 
The results of the experiments are: 
1. That for spra}ung to be efficient every portion of the surface 
infected must be thoroughly moistened with the disinfectant. 
2. That whitewashed surfaces require particular attention, being 
by far more difficult to disinfect than wood or paper. Solutions con- 
taining under 2 per cent'formalin are not reliable. 
Kokubo (45) compared Ij^sol or septoform and formalin soap con- 
taining 10 per cent and 25 per cent formalin with carbolic acid. He 
concluded that both formalin preparations were much more destruc- 
tive toward anthrax than carbolic acid, for the spores lived in a 3 per 
cent carbolic acid solution for twent^'-five days, while a 50 per cent 
solution of formalin soap killed in twenty-five minutes; but upon 
typhoid, streptococcus, and staph^dococcus the carbolic acid solution 
was slightly more active. 
Price (46) made a stud 3 ^of the influence of preservatives upon digest- 
ive enz^^mes, undertaken with the object of determining the minimum 
amount of formaldeh^^de, boric acid, borax, and salic}dic acid required 
'to preserve milk for forty-eight hours, the effect of the several pre- 
servatives upon the digestibilit}" of the milk being subsequent!}^ deter- 
mined by feeding the treated milk to calves. 
A number of experiments were also carried on to determine the 
minimum amount of formaldehyde that could be added to milk without 
affecting the action of certain enzymes in vitro, and, in addition, the 
effect of formaldehyde upon some of the more common bacteria was 
studied. 
His conclusions were: 
1. Formaldehyde added to milk, 4:20,000, preserves it for forty 
hours. 
2. Formaldehyde added to milk, 1:40,000, does not interfere with 
the digestibility when fed to calves. 
3. Milk preserved with formaldehyde fed to calves for long periods; 
calves remained healthy and gained in weight. 
4. Formaldehyde added to milk, 1: 2,500 or less, has no effect on the 
activity of the fresh enzymes, rennet, pepsin, pancreatin, and steapsin 
in Vitro. 
5. Formaldehyde plus starch, 1:2,500 or less, has no effect on the 
conversion of starch by ptyalin and amylopsin in vitro. 
