1870.] BROOME — ON CANADIAN PHOSPHATES. 261 



chloric acid (HCl.) will convert the same amount of phos- 

 phate into a soluble form as 40*0 parts of sulphuric acid 

 (SO3) ; whilst in the case of an apatite, a further amount 

 of vitriol is employed in the decomposition of fluoride of 

 calcium. By the employment of oil of vitriol to form 

 hydrochloric acid, by acting on common salt, and using the 

 product for the conversion of apatite, one part of vitriol may 

 be made to answer to 1*14 parts of vitriol applied by a direct 

 method ; and, in the decomposition of calcite, one part of 

 hydrochloric acid will answer to 1*096 parts of sulphuric 

 acid.* 



The saving of the acid employed, by the adoption of this 

 method, would more than counterbalance the extra expense, 

 and the chance of further loss by a multiplication of the 

 operations ; and another advantage over the ordinary process 

 would result from the lime salt produced being the soluble 

 chloride, and not insoluble (comparatively) gypsum, which, 

 by mechanically protecting a portion of the apatite from 

 complete conversion, doubtless accounts for the presence of 

 2*39 per cent, of unmodified lime-phosphate in the product 

 analysed.! 



The deliquescent properties of chloride of calcium have, 

 however, been found, by many English manufacturers, to 

 constitute a serious objection to the employment of hydro- 

 chloric acid : the product being apt to remain in a moist 

 unsaleable condition. 



It will not, however, be difficult to understand, from the 

 remarks already made, that combined ammoniacal, or potassic, 

 and phosphatic manures possess many advantages over simple 

 " superphosphates," and that such composts are likely more 

 and more to replace the ordinary soluble phosphates. English 

 and German manufacturers are, indeed, fast learning to pro- 

 duce such compounds ; and numerous nitrogenous substances 

 have been utilized for this purpose, including products 



* 40 parts of SO3 will produce from IS^a. CI. 3G-5 parts of H. CI. 



t Corrosion of chambers or vessels, and accessibility of the acid must 

 ia all cases be taken into account. 



