388 
IV, 1899, p. 60; Halliburton, Brit. Med. Jour., Yol. XI, 1900, p. 1; Rideal and 
Foulerton, Pub. Health, 1899, p. 554. 
(7) Cripp, Analyst, Yol. XXII, 1897, p. 182; Allen, Lancet, Yol. I. 1896, p. 
1516; Ringer, Jour, of Phys., 1895, p. 425; Chittenden, Diet, and Hyg. Gaz., 
1893, p. 25; Mayberry and Goldsmith, Chem. Centralbl., 1898, p. 69; Leffmann, 
Jour. Franklin Inst., 1899, p. 103; Weber, Jour. Am. Chem. Soc., 1902, p. 4; 
Chittenden and Gies, Am. Jour. Phys., 1898, p. 1; Tunnicliffe and Rosenheim, 
Jour. Hyg., 1901, p. 16S: Forstus, Archiv. of Hyg., Yol. XI, 1884, p. 75; Liebreich, 
Yierteljahrsschr. gericht. Medizin, 1900, p. 83. 
Eeference has already been made to the fact that Trillat (19) found 
that formaldehyde renders the casein of milk more or less indiges- 
tible. In this same connection PotteYin (23) has obseryed that for- 
maldehyde retards the coagulation of milk by rennin. Further 
experiments along this line have been made by Bliss and Xovy (24). 
These authors have confirmed the conclusions of PotteYin regarding 
the influence of formaldehyde on the coagulation of milk by rennin 
and ha Ye found that under the influence of formaldehyde the casein- 
ogen of milk is rapidly altered in such a way that either the rennin 
coagulation takes place only yery slowly or not at all. Thus if for- 
maldehyde in the proportion of 1 : 500 be allowed to act on milk for 
a few hours the milk is not coagulated on the addition of rennin. 
On the other hand, they observed that the rennin itself is not readily 
destroyed by formaldehyde, so that the delay or hindrance of the 
rennin coagulation of milk by formaldehyde is evidently due in some 
way to an alteration in the composition or properties of the casein- 
ogen. Similar experiments on the action of formaldehyde on the 
digestive ferments have been made by Halliburton (25) . He observed 
that 0.5 per cent of formaldehyde renders gastric digestion almost 
impossible, and 0.05 per cent delays it considerably. 'With 0.1 per 
cent formaldehyde no pancreatic digestion of fibrin occurs in twenty- 
four hours, and dilute solutions of the aldehyde delay the pancreatic 
digestion of starch. He also confirms the deleterious effects exerted 
by formaldehyde on the rennin coagulation of milk. 
Wiley and his coworkers have also studied the effect of formalde- 
hyde on the health of man. The results of this investigation, how- 
ever, have not yet been published. 
Concerning the toxic effects of boric acid and borax there is also the 
greatest difference of opinion among those who have made a study of 
the subject, and more recent investigations, despite their exhaustive 
character, have tended by no means to reconcile these opposing 
views, but if anything to accentuate them. For example, J. Xeu- 
mann (26) found that only very large doses of boric acid can cause 
death by gastroenteritis or from its effects on the nervous dr muscular 
systems. He therefore recommended it for the preservation of milk. 
According to Cyon (27) borax diminishes proteid metabolism, but all 
that can be learned from his work on the subject is, that metabolism 
