72 THE NUTRITIVE VALUE OF OIL-CAKES, ETC. 



It is to me exceedingly gratifying to find that I have had such 

 an attentive audience (cheers). 



Mr. T. D. ACLAND wished to ask a question, not so much for 

 his own information (as he had a decided opinion on the subject) 

 but to correct an opinion which prevailed in the minds of some 

 farmers ; viz. that the fat in the oil-cake made a fat farm that 

 was to say made wheat, and that the oil that did not go into the 

 animal went into the land. 



Professor VOELCKER There can be no question that oil-cake 

 is extremely useful, not only from the fat produced on the animal 

 but also on account of the nitrogenized and other constituents 

 which pass into the manure. However the superior quality of 

 the manure yielded by animals fed on oil-cake is not due to 

 the fat. In the first place, the fat is consumed in the animal 

 economy, but even if it were not, and passed away with the 

 excrement, it would be a very undesirable constituent in the 

 manure. I have no hesitation in saying that fat is worse than 

 useless as a manure. It ought to be well remembered that 

 fat, as a manuring constituent, is worse than nothing for this 

 reason, that it prevents the decomposition of animal substances 

 and of organic matters in general. We know very well that in 

 order for manure to enter into the plant it must be decomposed ; 

 and must be rendered soluble. But how do we prevent decom- 

 position ? Why by putting a layer of grease over potted meat. 



The MAYOR mentioned blubber. 



The PROFESSOR Blubber acts beneficially as a manure in 

 spite of the oil in it, because the oil is very impure, containing 

 extraneous matter, such as scales of fish, entrails, and other 

 animal matter. These, on decomposition, furnish ammonia, 

 which is a most desirable constituent in all good manures. In 

 some parts of the country gas-tar is largely used as a manure, 

 and preferred to gas-water. But gas-tar in its pure state is, I 

 have no hesitation in saying, injurious to vegetation. I would 

 not speak so decidedly if I had not made experiments on the 

 very point, but you can, by simple reasoning, show that tar 

 injures vegetation, for, like oil, tar consists only of carbon, 

 hydrogen, and a little oxygen. It does not contain anything 

 which is useful as a manure, and which is readily converted into 

 a constituent of manure. But gas-tar, in spite of its injurious 

 qualities, acts usefully, because ammoniacal water adheres to it. 

 It is better to use the ammoniacal liquor of gas-works, diluted with 

 considerable quantities of water say from ten to twenty parts 

 before applying it to the land (cheers). 



The meeting separated, after a vote of thanks to the Professor. 



London : Printed by W. CLOWES and SONS, Stamford Street, and Charing Cross. 



