THE PRESERVATION OF MILK 59 
contained boric acid. Several prosecutions in diflfcrcnt towns of England are recorded of cases in 
which similar quantities of boric acid have been used. 
Action of Boric Acid 
Professor Allen,* Professor of Physiology in Mason College, Birmingham, stated : — 
' Boric acid and its compounds are quite foreign to the animal body, and their presence must 
necessitate departure from the normal chemistry of life. The departure may be expected to 
consist partly in the formation of inert compounds of boric acid with calcium and magnesium 
(perhaps also iron), and the consequent removal of these indispensable metals from the economy. 
Whatever antiseptic may be used it should be remembered that, in order to obtain its due effect, 
there must be enough present to exert a decided influence on protoplasmic activity. This effect 
can hardly be expected to be beneficial to the tissues of the alimentary canal. Even the disinfection 
of the contents of the canal is a doubtful blessing in most cases, because the beneficial organisms 
are thereby destroyed. However harmless an occasional dose of boric acid (or one of its 
compounds) may be, it is evident that the case may be different when nearly every article of diet 
contains it.' 
The most systematic and complete experiments as to the action of boric acid and borax 
on the digestive ferments are those of Rideal and FouLERTON.t They used a mixture of boric 
acid (25 per cent.) and borax (75 per cent.). The following are abstracts of their results : — 
A. — Action on Amvlolytic Digestion 
I. — Salivary Digestion of Starch. 
Preservative. 
Strength. 
Retarding effect of preservative. 
Boric mixture 
I in 2000 
I „ 1000 
I 333 
1 1.7 per cent. 
12.2 „ 
I+.O 
The retarding effect was measured by the amount of sugar formed as compared with a 
control sample containing no preservative. 
2. — Digestion of Starch. 
Preservative. 
Amount. 
Retarding effect on action of 
Zymine. 
Pancreatine. 
Liquid Taka-diastase. 
Boric acid mixture 
I in 2000 
I „ 1000 
1 333 
22.8 per cent. 
37-0 
+9-2 
36.0 per cent. 
46.4 „ 
53-0 
67 per cent. 
73 
80 
* Report of tlie ' Lance ' Sanitary Commission on the Use of Antiseptic in Food, the ' Lancet,' Jan. 2nd, 1897, p. 58. 
f Public Health,' May, 1899. 
