91 

 ON THE OCCURRENCE OF PHOSPHATES IX NATURE 



George M. Dawson, D.S., F.G.S., Assoc. R.S.M., Etc., Assistant 

 Director Gkological Survey of Canada. 



Read 28th February, I884.. 



In proposing to review, in so short a paper, as this must necessarily 

 be, a subject so extensive as that indicated by the title, a difticult task 

 has been undertaken, and I cannot hope to do more than touch iipon its 

 main points. 



In the first place it may be proper to encpiire why phosphate 

 materials are now so much sought for as fertilizers. 



It has been said laconically that "Phosphorus is life," but this 

 like most bold generalizations is but a partial, and' even misleading 

 statement of the fact. Certain it is, however, that this element, 

 variously combined, is pi-esent in all living tissues, whether vegetable or 

 animal, and though in small quantity only, is absolutely essential to 

 these tissues, and, therefore, to the manifestation of life. Animals, 

 depending ultimately for their subsistence on plants, derive from these 

 their supplies of phosphorus, together with the other substances 

 necessary for their nutrition. Unlike the animal, the plant is capable 

 of living, ultimately, on inorganic substances, and while deriving a large 

 part of its food from the air, is absolutely dependent on the soil for 

 those incombustible constituents wliich, when the plant is burnt, 

 remain as ash. Without these the growth of the plant is impossible, 

 and it is therefore necessary to ensure a sufficient supply of them in the 

 soil. Phosphorus, in a state of combination, is one of t.hese, and that 

 to which I wish pai-ticularly to refer. 



In following this substance from the soil to the plant, from the 

 plant to the animal, and from the animal again to the soil, we find a 

 system of circulation, which, under certain conditions, might go on 

 indefinitely. In a .state of nature, this cycle is generally complete, Init it 

 is interfered with and broken by the present organization of humanity, 

 and more particularly by those arrangements which have resulted in 

 the massing of population in large towns. In these it is found neces- 

 sary to remove the effete and excrementitious matters by a system of 



