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reality injurious to the animal organism. T. M. Price (20), working 
in the Biochemic Division of the Bureau of Animal Industry, U. S. 
Department of Agriculture, has made a valuable contribution to this 
subject. He has studied the effect of some food preservatives on the 
action of the digestive enzymes, especially the effect of formaldehyde 
on the preservation of milk and the effect of this substance on the 
digestibility of the milk by the digestive enzymes in vitro and in the 
stomach of the calf. The following are the more important conclu- 
sions which he drew from these investigations: 
(1) Formaldehyde added to milk in the proportion of 1:20,000 pre- 
serves the milk for forty-eight hours. 
(2) Formaldehyde in milk in the proportion of 1:10,000 does not 
interfere with the digestion of the milk when it is fed to calves. 
(3) Upon feeding calves through a long period with milk preserved 
with formaldehyde the calves remained healthy and gained in weight. 
(4) Formaldehyde added to milk in the proportion of 1:2,500 or 
less has no effect on the activity of the fresh enzymes, rennet, pepsin, 
pancreatin, and steapsin in vitro. 
(5) Formaldehyde added to starch in the proportion of 1: 2,500 or 
less has no effect on the conversion of the starch into sugar by the 
enzymes ptyalin and amylopsin, in vitro. 
(6) Formaldehyde added to milk in sufficient quantity to preserve 
the milk for forty-eight hours — i. e., 1:20,000 — does not materially 
interfere with the action of the enzyme galactase, in vitro. 
(7) Formaldehyde added to milk in the proportion of 1:20,000 
prevents the development of the more common bacteria found in 
milk and when added in the proportion of 1:1,560 it kills these 
bacteria. 
(8) Formaldehyde may be added to milk in sufficient quantities 
to preserve milk and to prevent the development of some of the more 
common bacteria — i. e., 1:10,000 — and still have no deleterious 
effect on the digestibilitv of the milk for calves. 
(9) Formaldehyde should never be fed to calves as a milk pre- 
servative stronger that 1 part of formaldehyde to 10,000 parts of 
milk. 
According to Price the results obtained by the majority of inves- 
tigators who have experimented with formaldehyde are of no value, 
inasmuch as at least the majority of them employed formaldehyde 
solutions varying in concentration from 1 : 25 to 1 : 2,000, these quan- 
tities being very much larger than the quantities of formaldehyde 
used in the preservation of milk in practice. At the-close of his arti- 
cle Price gives the following bibliography on the subject: 
(1) Salkowski u. Hahn, Pfliiger’s Archiv., Bd. LIX u. LXIII; Moraczewski, Zeit- 
schr. f. physiol. Chem., B. XX. 
(2) Babcock and Russell, Wis. Ann. Rept. Ex. Stat., Yol. XIV, 1897, p. 161. 
