406 
Preservatives for Cream. 
though gelatine does so more effectually than glycerine : 2^ ounces of 
gelatine steeped in 2 or 3 ounces of water, and dissolved in a solution 
of 1 ounce of mixed borax and boracic acid in a pint of hot water, 
will, when cool, form a jelly which will keep any length of time. A 
teaspoonful of the jelly dissolved will preserve a pint of cream for 
from seven to nine days. If these mixtures are used they should 
be added very sparingly, as a large quantity would artificially thicken 
the cream, and enable a poor thin sample to be palmed off as a rich 
double cream, though it might keep for a considerable time. 
It is doubtful whether it is desirable to keep milk or cream for 
any length of time. For sterilisation and the use of preservatives 
only destroy or arrest the lactic acid ferment, and do not affect the 
numerous other bacteria which go on multiplying with age. It is 
therefore reasonable to suppose that, after a time, milk and cream 
may not be wholesome^ even though they may not have turned 
sour. 
Milk and cream are essentially perishable articles, and are 
intended for immediate consumption, though by the careful and 
limited use of preservatives they may be kept for a short time with- 
out any deleterious effect, 
J. F. Curtis-Hayward. 
RATIONAL POTATO CULTURE. 
For some years past M. Aime Girard has devoted himself to the 
improvement of potato culture in France, and, according to the reports 
published by him from time to time, he has achieved remarkable 
success in this direction. The last report, 1 showing the results of 
M. Girard’s experiments during the season of 1892, is particularly 
interesting, and has attracted considerable attention ; so that it seems 
desirable to give a short account of its main points and conclusions 
for the benefit of potato growers in this country. 
M. Girard is a scientific as well as a thoroughly practical agri- 
culturist, who, it will be remembered, was the first to demonstrate 
the advantage of applications of a mixture of sulphate of copper and 
lime, bouillie bordelaise, to prevent and cure the potato disease. 
This report, however, does not deal specifically with this treatment 
of potato plants, nor are the exceptional crops recorded alleged to be 
principally due to the use of bouillie bordelaise. The application of 
the bouillie bordelaise was made in many cases by way of preventing 
disease. There was so very little potato disease in France in 1892 
that there was no occasion for repeated dressings for purposes of 
cure. 
For ten years M. Girard has been writing upon the necessity of 
increasing the yield of the French potato crop. He has pointed out that 
1 Amelioration de la Culture de la Pomme de terre industrielle et fourragere 
en France. Eestiltats de la camp ague, 1892, par M. Aime Girard. 
