72 



SOURCE OF MINERAL PHOSPHATES. 



The source of phosphatic manures, such as are found in the mineral 

 form in various deposits, is a subject that has attracted much attention 

 on the part of chemists and agriculturists. Of course, as regards guano, 

 the phosphoric acid is readily referable to the excrement and offal of 

 sea-fowl. Certain guano, such as Soinbrerite, is derived from the action 

 of water on this matter, and the subjacent calcareous coral rocks. It 

 is thought that much of the palaeazoic phosphatic rooks may hav^e been 

 produced in this way; at any rate, those whi(;hhave been formed subse- 

 quent to the evolution of terrestrial and vertebrate animals. There are, 

 however, many beds the origin of which cannot be referred to any of 

 the causes just mentioned. Professor Dyer, in an article on this subject 

 in "Nature," suggests the same view that was presented at the late 

 meeting of the American Association by Professor Kerr, namely, that 

 the brachiopods may have supplied a large percentage, the recent Lin- 

 gula, as is well known, having over eighty per cent, of ])hosphate of 

 lime in the mineral ingredient of its shell. In fact, he is of the oi)inion 

 that the large quantities of phospliate of lime in the Laurentian and 

 Silurian, as well as in the Devonian and carboniferous strata, are de- 

 rived from this source. In the luesozoic and tertiary strata, instead of 

 finding the mineral phosphate in veins and beds, it occurs mostly in the 

 form of nodules. Mr. Dyer coincides with the hypothesis previously 

 presented by Mr. Lankester, based upon the proj)erty possessed by clay 

 of detaching phosphate of lime from its solutiou in carbonated water. 

 The nodules in question are believed to be bits of clay, which have been 

 imbedded with great quantities of bones, as perhai)s, also, with seaweed, 

 from which, by the intervention of gas-chargeil water, they have extracted 

 the phosphate. Hence the almost invariable occurrence of beds of 

 phos})hatic nodules near argillaceous strata. 



This same view has been used to explain the origin of the phosphatic 

 nodule beds which have lately been detected in immense extent in the 

 vicinity of the city of Charleston, forming a mineral fertilizer which is 

 coming into very extended use. Among other applications, this sub- 

 stance is ground up and mixed with prepared fish, and converted into 

 an excellent manure for worn-out lands. 



UTILIZATION OF COTTON SEED. 



Various movements have been made of late years looking toward the 

 utilization of cotton seed, usually considered a burden to the cotton- 

 planter, and in getting rid of which great ingenuity has been expended. 

 Among the more recent i)iopositions of the kind, that of the emj)loy- 

 ment of the adhering cotton, and, ])erhaps, of the woody material, in 

 the manufacture of paper, has been brought forward, and a calculation 

 I)resented as to the number of tons of paper stock that could thus be 

 introduced into the market. Lately, large establishments have been 

 started in the South for the i)urpose of obtaining the oil from the seed, 

 the refuse being converted iuto oil-cake for fattening cattle. The crude 

 oil brings in Nevv York from thirty-five to forty cents a gallon, and the 

 oil-cake commands nearly the price of corn, being said to equal it in 

 its fatten uig qualities. Shipments of the seeds have been made recently 

 in great quantity to Liverpool, from New Orleans, one vessel taking' 

 over ten thousand sacks of the seeds, and about one thousand sacks of 

 oil-cake; and it is expected that these shipments will be followed up on 

 a large scale. As over two million tons of cotton seed are every year 

 produced in the South, we may well imagine how important it will be 



