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afforded for carrying out various experiments at the homestead and 

 in the field, which were supplemented by collateral laboratory investi- 

 gations. He had already commenced an investigation into the com- 

 position of farmyard manure, and as to the changes it undergoes 

 under various circumstances, such as in contact with different 

 soils. 



Erom the results obtained in these inquiries, he was led to investi- 

 gate the absorptive powers of different soils of known composition ; 

 and he showed that the most important soluble constituents of manures 

 are rendered less soluble, but not quite insoluble, when applied to 

 the soil. 



In the course of his inquiries, he instituted numerous field experi- 

 ments with different manures, on different crops, on the College 

 farm; and he also endeavoured to enlist the co-operation of intelligent 

 practical farmers in different localities in the conduct of field experi- 

 ments. 



In 1878, he became responsible for the conduct of the systematic 

 series of field experiments which, in the previous year, had been 

 commenced at Woburn, on behalf of the Royal Agricultural Society, 

 at the instance, and at the cost, of His Grace the Duke of Bedford. 

 To the last he took the deepest interest in the management and in 

 the results of these experiments. 



Very soon after he had devoted himself to agricultural chemistry, 

 Dr. Voelcker commenced to pay attention to the various aspects of 

 the subject of the feeding of animals. He had not the same facilities, 

 either for conducting feeding experiments himself, or for arranging 

 with others to conduct them, that he had in case of field experiments 

 with manures. He, however, not only wrote and lectured on the 

 chemistry of the feeding process, but he analysed a very large number 

 of food stuffs, both home-grown and imported. He determined the 

 composition, in much detail, of most of the crops grown on the farm 

 as food, of new plants proposed to be grown as food- crops, of hay, of 

 various descriptions of straw, of certain refuse matters, and so on; 

 discussing at length their actual and comparative feeding value, as 

 deduced from the results of his laboratory investigations. 



But perhaps the most essential service he rendered, in connexion 

 with the composition and value of food-stuffs, was by his most elabo- 

 rate investigations, microscopic and chemical, of the various matters 

 entering into the composition of feeding-cakes, by his numerous 

 analyses of the various cakes themselves, and by his fearless and per- 

 sistent exposure of what he considered injurious, or against the 

 feeder's interest, in the manufacture or composition of such articles, 

 whether resulting from carelessness, ignorance, or fraud. 



The subject of Milk and the Dairy, which is one of rapidly growing 

 importance to the British farmer, was early taken up by Dr. Voelcker, 



