VALUATION OF MANURES. 373 



The attempt to fix a precise value upon any manurial constituent 

 is hedged about with practical difficulties. 



In regard to the next one to be considered, viz., insoluble phos- 

 phoric acid, it is compai'atively easy to set a price upon phosphate 

 of lime in raw bone, and just as easy upon the phosphoric acid 

 which constitutes less than half of the phosphate ; but this is not 

 the only source from which it is derived. In fact, only a very 

 small proportion indeed of the insoluble phosphoric acid of com- 

 merce comes from raw bone. Moreover, the cost of phosphate of 

 lime in most other substances is less than in bone, and less in 

 some of them than in others ; and not only is the price less but the 

 agricultural value is less also, and varies more or less in all. 



This variation is due to the greater or less d^^ee of solubility 

 of the phosphate as it exists in one or another of the substances 

 containing it. In raw bone, when finely ground, although not 

 immediately soluble in pure water, and therefore technically called 

 insoluble, it can be appropriated by growing plants during the 



potash cost nine and a half cents a pound, while in American ash it costs thirteen and a 

 half cents per pound." 



There is a loss or drain of potash from our farms hardly thought of hitherto, and even 

 more seldom utilized, in a peculiar excretion of sheep. The following is quoted from 

 the report above named: 



" It is well known that sheep draw from tho land on which they graze a considerable 

 quantity of potash, which, after circulating in their blood, is excreted from the skin 

 with the sweat, in combination with which it is deposited in the wool. Chevroul pointed 

 out that this peculiar compound, called by the French ' Suint,' forms no less than a third 

 of the weight of raw merino wool, from which it may be readily dissolved out by simple 

 immersion in cold water. In coarser wools it is less abundant, and according to M. M. 

 Maumene and Rogelet, potassic sudorate, or suint, of ordinary wools forms, on the 

 average, about fifteen per cent, of the raw lleece. This compound was formerly re- 

 garded as a soap, doubtless because wool contains, besides the suint, a considerable 

 amount (about 8^ per cent.) of greasy matter. This grease, however, is, in fact, com- 

 bined with earthy matter, chiefly lime, as an insoluble soap. The soluble sudorate is a 

 neutral salt, resulting frum the combination of potaeh with a peculiar animal acid, of 

 which little is known beyond the fact that it contains nitrogen. 



At the great seats of the woollen miinufacture in Franco, as at Rheims, Elbceuf and 

 Fourmies, the new industry of M. M. Maumene and Rogelet is either established or in 

 course of establishment. * * * An ordinary fleece weighing about four kilos, 

 contains about 600 grams (above 20 ounces) of sudorate of potassium, or suint. This 

 contains about one-third of its weight of pure potash," (say seven ounces.) 



The manufacturers of the three above named places wa.sh the fleeces of G, 750,000 .sheep, 

 and it is computed that these p.re about one-seventh of all in France; also that if all the 

 potash from this source was saved France would derive from it all the potash she re- 

 quires. It is to be hoped that, either by the efforts of farmers or of wool manufacturers, 

 this source of fertilization may not be longer overlooked. 



