796 
IFlotes, Communications, anb 
■(Reviews. 
THE FERMENTATIONS OF MILK. 
An important memoir “ On the Fermentations of Milk ” has been 
issued by the United States Department of Agriculture as Experi- 
ment Station Bulletin No. 9 for the current year. In this pub- 
lication, which extends to seventy-five 8vo pages, Dr. H. W. Conn, 
Professor of Biology in the Wesleyan University, gives a most 
useful digest of the original work that has been accomplished up to 
the present date in connection with this subject. In a biblio- 
graphical appendix, which will be hardly less useful to the scientific 
inquirer than the digest itself to the ordinary reader. Dr. Conn 
adds a list of 137 original papers, recording the work of dififerent 
experimenters, but even this professes to be only a selection of the 
moi’e important references from a much larger list. From this fact, 
the extreme intricacy of the subject and the great amount of 
labour that has been expended to give us the very partial know- 
ledge which we at present possess may easily be inferred. 
No doubt it is in great measure due to this intricacy that so 
many loose and inaccurate and, in many cases, absolutely erroneous 
ideas are current in reference even to the two commonest changes 
to which milk is subject — souring by keeping and curdling by 
rennet, — and this not only amongst practical dairymen and farmers, 
but also amongst contributors to the agricultural press, and those 
lecturers who have essayed the difficult task of endeavouring to 
popularise the scientific study of agriculture and dairying in 
country schools and technical classes. 
To these and many others it may be useful if we attempt to 
gather together in a few pages, and in a readable form, the most 
valuable and conspicuous fruit of the labours which Dr. Conn has 
so exhaustively and critically examined for us. 
The COMPOSITION OP MILK need not detain us long, but must be 
glanced at in order to make plain what follows, and to facilitate 
reference to those points which are still matter of controversy. The 
annexed table, which the writer is accustomed to use for purposes 
of instruction, may save a longer explanation : — 
