384 
instances they involve contradictions; that the boric acid and borax 
were not administered with food, but were taken directly into the 
system, and that in certain instances the real cause of the disturbance 
attributed to borax and boric acid was in all probability badly pre- 
served meat; and by way of further confuting the results reached by' 
other observers regarding the toxic action of . boric acid and borax be 
cites the findings of Tunnidiffe and Rosenheim, to the effect that 
children increased in weight on a diet containing borax and boracic 
acid. Liebreich is of the opinion, therefore, that practical experience 
justifies the use of boric acid and borax as a food preservative. Wiley, 
Bigelow, and others (37), as the result of their study of the effect of 
boric acid and borax on man, have found that while the persons under 
experiment were in many instances made temporarily ill by the quan- 
tities of boric acid administered, at the end of the year, after the final 
after period, they appeared to be, and so expressed themselves, in 
better physical condition than when they entered on the experi- 
mental work. 
It has already been pointed out that salicylic acid and benzoic acid 
are only rarely used as milk preservatives. This is fortunate, since 
both of these substances must be looked upon as toxic, to a degree at- 
least, and the former, at least, seems to be more or less cumulative in 
its toxic effects upon the system. The injurious effects resulting 
from continuous small daily doses of salicylic acid were first pointed 
out by Brouardel (39), who made a plea for its discontinuance as a 
food preservative and for more thorough and systematic examina- 
tions of preserved foodstuffs by chemists and health officers. The 
effect of salicylic acid and the salicylates on man has also been investi- 
gated quite recently by Doctor Wiley (40) and his co workers at the 
hygienic table. He points out in his general conclusions ' that there 
has been a general consensus of opinion among scientists and medical 
authorities that salicylic acid and its compounds are very harmful 
substances ' and that the prejudice against them is perhaps greater 
than against any other form of food preservatives. While he is still 
inclined to look upon it as a harmful substance, it is probably of less 
virulence than has heretofore been supposed. Attention has already 
been called to the use of hydrogen peroxide in the sterilization of 
milk. In its 3 per cent solution this substance has been employed by 
Budde (14) to sterilize milk at somewhat lower temperatures than 
those employed in the ordinary processes of pasteurization, and 
attempts have also been made to remove all traces of the peroxide 
remaining in the milk after such treatment. According to Lakin (41), 
however, these attempts have not proven practicable, and this author 
therefore objects to Budde’s process of sterilizing milk on the ground 
