The Phosphates of America. Ill 



ing for the sake of variety that our chamber acid is of 52 B. 

 strength instead of 50 B., we shall find that 



79.401bs. phosphate lime X .965 = 76.62 Ibs. 



5.48 " carbonate " X 1.495= 8.19 " 



3.00 " phosphates of iron and alumina combined X 1.839 = 5.52 " 



0.72 " carbonate of magnesia. X 1.775= 1.28 " 



3.20 " fluoride of calcium X 1.916= 6.13 " 



The total quantity of 52 B. acid required for every 100 

 Ibs. of raw material, in order to bring the insol- 

 uble phosphates into a soluble form, is therefore ... 97.74 " 



It would thus appear to the unobserving, that a mixture of one 

 ton each of the raw materials produces, after allowing for certain 

 losses in the fabrication such as evaporation about two tons of 

 fertilizer, and that we have gone to unnecessary trouble to dem- 

 onstrate a very simple fact. Such " rule-of -thumb " reasoning is 

 no doubt responsible for the many bad " supers " we meet with in. 

 the trade, and the present is therefore the right time to ask what 

 kind of a fertilizer has been thus prepared. As a matter of abso- 

 lute fact, no question is so little understood by the majority of 

 those who should be able to answer it, and yet no other is of so 

 much importance. 



We have been taught by chemistry that certain qualities are 

 essential in a fertilizer in order that it may produce its results 

 with rapidity and economy. Without a sufficient knowledge of the 

 reactions involved, how can the possession of these qualities be in- 

 variably assured and conscientiously guaranteed ? 



Let us therefore examine a little more closely into the nature 

 of this very complicated body. 



As revealed to us in our own practice and by the experience of 

 other chemists, there can be no reasonable doubt that the tricalcic 

 phosphates of mineral origin, when treated with sulphuric acid, 

 become partially or wholly changed into three distinct forms : 



1. Free phosphoric acid soluble in water. 



2. Acid phosphate of lime soluble in water. 



3. Neutral phosphate of lime insoluble in water, but readily 

 soluble in neutral citrate of ammonia. 



There can also be no doubt that the nature and extent of this 

 change, as well as the physical condition of the mass resulting 

 from the mixture, will depend entirely upon two factors : 



A. The skill and intelligence of the practical operator. 



B. The nature and composition of the phosphate to be handled. 



