PrOCSSDINGS of the PoLTTECHyiC ASSOCIATION. 945 



quantities, especially in Norway, Sweden, Spain, Canada, and also 

 in other localities. It has, of late years, been eagerly sought after to 

 supply the great demand for pliosphates as fertilizers. 



It is, however, well known that neither l)one, coprolite, nor 

 apatite is applied to the soil in its insoluble state, being, in that con- 

 dition, comparatively useless as regards the nutrition of plants. In 

 order to render them fit for agricultural purposes, they must be con- 

 rerted into the soluble superphosphate. In order to eifect this, 

 100 pounds are treated with sixty-three pounds of oil of vitriol. 

 TJie soluble superphosphate of lime i« obtained, which product is 

 generally employed for fertilizing lands. 



The quantity of superpliosphate of lime at the present day manu- 

 factured in England, the United States, France and Germany, is said 

 to be 1,000 tons per d»)^ This rate of production, at an average price of 

 forty dollars per ton would amount to the sum of $14,000,000 per 

 annum. It is now well known that the guano supply is gradually 

 diminishing. "We make no doubt that, with the increase of population 

 and the extended cultivation of barren and worn out soils, the demand 

 for superphosphate of lime will reach at least $20,000,000 per annum. 

 This shows the importance of utilizing nature's gifts to their fullest 

 extent. The consumption of superphosphate of lime, in place of other 

 substances used in the arts, is now comparatively small, but may, at no 

 distant day, find a large application in the manufacture of phosphorus 

 and phosphate of soda. A few years ago there was a good deal of inquiry 

 made for phosphate of soda for the use of distillers, whose experi- 

 ments proved that an addition of it would not alone accelerate the 

 process of fermentation, but also produce an increase in the yield, and 

 it is the main ingredient in Prof. Horsford's baking powder, -so well 

 explained in his last lecture before the American Institute. Some 

 fine crystals of phos]iliate of soda were obtained from Canadian 

 apatite; nor is there any reason why phosphorus, not yet manufac- 

 tured in this country, but imported from German}^ and France tto 

 the value of $100,000 per annum, should not be obtained 'in 

 this country from the native mineral.* In the manufacture 'e^ 

 phosphorus the mineral apatite is first converted into a super- 



♦ Phosphorus had been already discovered hi 1669, by Brand, in Hamburg. Boerhave, in 1753,<icll8 



"as how to produce fire in a cold body solely by exposing it to the air. He states that there\V7«8 



nothing more remarlcable, setting gunpowder aside, than that a body should be produced, ■wtijeh 



though cold, like all other things when kept from the air, is no sooner exposed thereto than itte^kes 



Are and emits flames, witbcut the mediation -ef any other body, or-witbout mecbanical-attrltviin or 



-application of fire to it. 



[Inst.] '60 



