M.—AGRICULTURE 261 
shown that grass can be rapidly dried in a band drier at a temperature of 
200° approximately, with scarcely any loss of digestibility or nutritive 
value and, what is more surprising, with only a small loss of the carotene 
content. It was also shown that the carotene content and the nitrogen 
content of pasture herbage were associated, grass of high nitrogen content 
being rich in carotene, so that by properly balanced manuring the carotene 
content of the pasture might be maintained at a higher level. A winter 
feeding experiment with cows was then arranged and the artificially dried 
grass was used to replace an equivalent amount of the ordinary food, with 
the result that the carotene and Vitamin A content of the butter was kept up. 
This effect was not produced by the addition of ordinary green silage. 
The importance to the public health of being able to produce in winter 
butter which, in regard to colour and Vitamin A content, is equal to the 
butter produced in summer from grass-fed cows, can hardly be over- 
estimated. 
As regards vitamins generally, the most important problems are the 
differentiation of the different vitamins and the determination of the 
vitamin requirements of man and the higher animals. By the time this 
is done, it appears probable that there will be an abundant supply of 
pure vitamins to compensate for the deficiencies in the ordinary rations. 
While talking of nutrition, the part played by the mineral matter of the 
food must also be mentioned and the necessity for maintaining a correct 
ratio between the basic and acidic constituents. Much important work 
has been carried out in this country in recent years by the Rowett Institute 
and the Animal Nutrition Research Institute at Cambridge on the mineral 
content of pastures. In his Presidential Address at Bristol in 1930 
Prof. Du Toit described the far-reaching results of Theiler’s work in 
South Africa on phosphorus deficiency, and referred also to Aston’s 
work on iron deficiency in New Zealand. 
AGRICULTURAL DEVELOPMENT. 
Sufficient has been said of the scientific advances in recent years to 
indicate the great importance of their application, when possible, to 
agricultural industry. At one time it was only too apparent that there 
existed a long lag between scientific discovery and its application in agri- 
cultural research, but this has diminished considerably in recent years ; 
indeed, it may now be said that any new line of work is almost at once 
turned to account in agricultural investigation. 
This agricultural work is undertaken mainly at the new agricultural 
research institutes, although a considerable amount of work is still carried 
out at the universities and the agricultural colleges. 
The development of these research institutes has been one of the most 
marked advances connected with agricultural science which have taken 
place in recent years. 
In Scotland alone, for example, institutes have been established within 
the last few years for research in animal nutrition, in animal diseases, in 
animal genetics, in plant breeding, in dairying and in soil science, and the 
progress in England has been equally great. 
How are the results of these investigations brought before the farmer 
