REPORT OF THE CHEMIST. 73 



Auali/sis of a so-called "(juano.'^ 



Water .- , 14.00 



Or;i;aiiic and volatile * 2o. 05 



Soluble in water and acids ." Til. 01 



Saudaudclay ! 10.98 



100. 00 



The following' were the valuable mineral constituents: 



Per cent. 



Pliosplioric acid, soluble (P2O5) 5.92 



Phosphoric acid, reverted (P2OO G. 34 



Phosphoric acid, insoluble (P2O5) G. 27 



Potassium oxide (KjO) 2.23 



2. — Animal and vegetable refuse. 



Dried blood, meat scrajis, fisli and fish-offal, gelatine and glue waste, 

 the pomace left after expressing the oil from castor, linseed, and cotton 

 seeds, are all valuable sources of nitrogen . Yery much depends, however, 

 upon their mechanical condition, and in estimating their value due regard 

 must be had to their fineness, freedom from moisture, &c. 



Of very much lower and more variable value aresuch substances as hair, 

 wool, and shoddy waste, clippings of hides, horn scraps, &c. Although 

 these substances may furnish, upon analysis, considerable potential 

 ammonia, their comjiact texture or indestructible character prevents 

 them from decaying rapidly enough to be of any marked value to the 

 growing crop. An examination of shoddy waste gave the following 

 results: 



"Slwddy ivaste." 

 From "West Eiding Shoddy Works Company," De'wslinrjr, En;^l.-:i:l. 



It is very doubtful whether this would prove of any direct fertilizing 

 value. 



A good many other waste products are used with varying success. 

 Great care should be taken in their selection, and, if pos.sible, the opin- 

 ion of an experienced chemist should be had. The third form in which 

 nitrogen can be applied to plants is in the form of nitrates. 



c. Nitrates. 



The only cheap nitrate at present used as a fertilizer is nitrate of 

 sodium (iN^aNOs), commonly known as Chili saltpeter or Chili niter. 

 Its value depends upon its percentage of nitrogen. When perfectly 

 pure and dry this salt contains 1G.47 per cent, of nitrogen ; but in prac- 

 tice this amount is not reached, owing to the presence of impurities and 

 to the fact that this salt readily absorbs water from the air. ISfitrates 

 are the most expensive sources of nitrogen. 



II. — POTASH SALTS. 



Equally valuable and necessary to the growth of a plant are salts of 

 potash. They are valuable in proportion to the amount of potassium 



"Potential ainmonia in organic matter, 5.40 per cent. 



1 Contains of potential ammonia, 2.76 per cent. ; 2.73 per cent. 



