212 MASSACHUSETTS HORTICULTURAL SOCIETY. 



If m}' figures are not wrong, the cow manure is not a cheap 

 source of plant food ; it would have to be looked upon as more 

 costly than commercial fertilizers were it not for the large amount 

 of humus-forming material that it contains ; this may offset the 

 high cost of the important plant nutrients in it. But then we have 

 just as much of this humus-forming material in horse manure ; and 

 the important plant nutrients in that, instead of being more costly 

 than in the commercinl fertilizer, are actuallj^ cheaper. The night- 

 soil costs nothing except for the hauling ; the plant food in it is 

 remarkably cheap, costing only about a fifth as much as in horse 

 manure ; and one can see no reason wh}' a pound of nitrogen in it 

 should not be just as good for ci'op production as a pound of the 

 same nutrient in horse manure. Rockweed is an expensive manure, 

 much more so than commercial manures, while the plant food in 

 it certainh' cannot be any more available or valuable than in fine 

 bone meal, or in good horse manure, or than in the fish-chum, 

 which provides nitrogen and phosphoric acid at half the cost. 



Hen manure is another expensive fertilizer : its plant food costs 

 more than that in any other fertilizer, natural or artificial. Even 

 nitrogen in ammonia salts costs only twentj'-two cents, and phos- 

 phoric acid in the best superphosphate only ten cents a pound. 

 From my point of view I should say that a great deal more was 

 paid for that manure than it was worth. As to the tanners' waste 

 I had to do some guessing ; I took it to be most!}' hair and clip- 

 pings of fresh skins ; it cost nothing, except for the hauling. If 

 I was right in ni}' conjecture as to its. character, it is rich in both 

 nitrogen and phosphoric acid, and is by far the cheapest manure 

 of all ; but its action may be much slower than many of the other 

 manures in the list, which would detract from its value. Granting 

 all that, it would still appear to be a very cheap manure. 



Making all due allowance throughout these estimates for the 

 possible deviations from the general average composition of such 

 materials, I still aflSrm that where thej' come out so widely apart as 

 the}' do in some cases, the}' indicate real and undoubted differ- 

 ences in the cost of the plant food, that may be of considerable 

 practical importance to the buyer of such manures. 



We may look for a moment, before I close, at this same matter 

 from another point of view. On the University farm at Cornell, 

 Professor Roberts, by a careful system of saving and housing his 

 stable manure, and rich feeding of his stock, largely milch cows, 

 has obtained a product that, analyzed in my laboratory, was found 



