( 262 ) 
[April, 
ANALYSES OF BOOKS, 
The Most Important Articles of Food and Beverages , with their 
Impurities and Sophistications. A Practical Guide to their 
Detection.* By Oscar Dietzsch, Chemist to the Industrial 
Museum of Zurich. Zurich : Oscar Fiissli and Co. 
Of all departments of chemistry that which bears upon public 
health, and upon the detection of adulterations and impurities in 
food and in other articles of general consumption, has received 
in England the largest relative share of attention. Hence we 
doubt not that medical practitioners, chemists, and even the 
outside public, will take an interest in a foreign work which in a 
short time has reached its third edition, and which, as we learn 
from the Preface, is about to be translated into the English, 
French, and even the Russian languages. The author, who evi- 
dently possesses very extensive experience in this branch of 
analysis, addresses himself solely to professional men, and does 
not waste space on the task of teaching outsiders how to perform 
operations which unless done accurately had much better never 
be attempted at all. 
The first article examined is milk. Here we notice with regret 
the great weight which the author lays upon the specific gravity 
of the sample, and consequently upon the use of the lactometer. 
We had hoped that the arguments against this instrument were 
so widely known as for ever to deprive it of any higher rank than 
that of a scientific toy. Dr. Dietzsch points out, however, very 
judiciously, that statements made concerning the milk of indivi- 
dual cows may have a certain value from a physiological or a 
pathological point of view, but are utterly useless as regards 
market-milk, which in these days, in towns at least, is a mixture 
of the milk of many cows, where individual and exceptional vari- 
ations are of course lost in the average. If, as is alleged, MM. 
Vernois and Becquerel, when examining different sorts of 
market-milk in Paris, found a sample of sp. gr. roi6, and, with- 
out ascertaining anything concerning its origin, analysed it as a 
genuine milk and inserted the results in their tables, they were 
guilty of a piece of negligence which cannot be too gravely 
reprehended. 
The author does not give any opinion as to the constancy of 
* Die Wichtigsten Nahrungsmittel und Getranke, deren Verunreinigungeq 
und Verfal^chupgen. Praktisch^r Wegweiser zu dtren Entdeckupg. 
