262 THE CANADIAN NATURALIST. [Sept. 



obtained from blood, or animal refuse, (as for example, the 

 waste of the enormous butcheries at Chicago) ; others from 

 the refuse of tan-jards ; from the ammoniacal products of 

 gas-works ; and a number of the residua resulting from 

 various chemical manufactories. " Superphosphates," pro- 

 duced by the action of muriatic acid upon apatites, might 

 readily be dried up by these materials ; thus overcoming the 

 objections arising from the pastey condition of the product, 

 and, at the same time nearly doubling the value of the 

 fertilizer.* 



Sulphurous acid, also, produced directly from the roasting 

 of pyrites, has been applied successfully for the formation of 

 " superphosphates " from animal sources ; but further ex- 

 periments on the subject are necessary, to shew whether it 

 would, or would not, be applicable for the conversion of 

 apatites or other mineral phosphates. 



Before concluding the subject, one very ingenious process, 

 patented by MM. M. L. Henrionnet and L. C. Bobhque, in 

 Nov. 1860, t (see Patent Abridgements, in Appendix to 

 Richardson and Watt's Chemical Technology) may be 

 noticed, in which hydrochloric acid, generated during the 

 process itself, by the reaction taking place between steam, 

 silicic acid, and common salt, is employed in the manufacture 

 of soluble phosphates. 



The finely pulverized apatite, mixed with 2-3rd3 parts of 

 common salt, and about 18 per cent, of silica, is heated, 

 ji a current of steam, upon the bed of a reverberatory 

 furnace ; when the following reactions are produced : 



(a) Si 02 + Na Cl-t-H 0=H CUNa 0, Si O2 



(b) 8 Ca 0, PC, + 2 H Cl=Ca 0, 2 HO, POj + 2 Ca CL 



* Sawdust, previously saturated with sulphuric acid, has been 

 patented, by Mes&rs. Sugden and Maryatt, for the absorption of am- 

 monia from coal-gas. "When exhausted, it contains from 40 to 60 per 

 cent, of sulphate of ammonia, and is valued at from $'25 to $30 per 

 ton of 2,240 lbs.— Tide Report on Industrial Chemistry CParis Exposi- 

 tion) 1867, by J. Lawrence Smith, U. S. Commissioner. 



+ Berzelius Jahreabericht, ' 



