32 TALKS OX MANURES. 



Other manure was found to contain, in \vli:itcver form, 7 per cent 

 of nitrof^en, tlie clieniist reported that lie found in it 8i per cent 

 of 'potential' ammonia. Dried blood contains no ammonia, but 

 if it contained 14 per cent of nitrogen, the chemist would be justi- 

 fied in saying it contained 17 per cent of potential ammonia, from 

 the fact that tlie dried blood, by fermentation, is capable of yield- 

 ing this amount of ammonia. We say a ton of conmion horse- 

 manure contains 10 or 12 lbs. of potential ammonia. If perfectly 

 fresh, it may not conUiin a particle of ammonia ; bat it contains 

 nitrogen enough to produce, by fermentation, 10 or 12 lbs. of am- 

 monia. And when it is said that drj' swamp-muck coiitains, on 

 the average, 2.07 per cent of potential ammonia, it simply means 

 that it contains nitrogen enoui:h to produce this amount of am- 

 monia. In point of fact, I suppose muck, when dug fresh from 

 the swamp, contains no ammonia. Ammonia is quite .soluble in 

 water, and if there was any ammonia in the swamp-muck, it 

 would soon be wasiied out. The nitrogen, or ' jjotcntial ammonia,' 

 in the muck exists in an inert, insoluble form, ar.d bef<»rc the 

 muck will yield up this nitrogen to plants, it is neceasary, in some 

 way, to ferment or decompose it. But this is a point we will 

 discuss at a future meeting." 



CHAPTER VII. 

 TILLAGE IS MANURE. 



The Doctor has been invited to deliver a lecture on manure 

 before our local Farmers' Club. " The etymological meaning of 

 the word manure," he said, " is hand labor, from main, hand, and 

 outrer, to work. To manure the land originally meant to culti- 

 vate it, to hoe, to dig, to plow, to harrow, or stir it in any way so 

 as to expose its particles to the oxygen of the atmosphere, ano 

 thus render its latent elements assimilable by plants. 



" When our first parent," he continued, " was sent forth from 

 the Garden of Eden to till the ground from whence he was taken, 

 he probably did not know that the means necessary to kill the 

 thorns and thistles enhanced the productiveness of the soil, yet 

 such was undoubtedly the case. 



