144 Analysis and Valuation of Manures [233 



Subtract soluble P 2 5 from CaP 2 6 ; result = lime in 

 soluble phosphate. 



Subtract insoluble P 2 5 from insoluble Ca 2 P 2 8 ; result 

 = lime in insoluble phosphate. 



Add CaO in CaP 2 6 to CaO in Ca 3 P 2 8 ; result = CaO 

 combined with P 2 5 . 



Subtract this last amount from total CaO ; result = CaO 

 combined with S0 3 . Multiply this amount by 17 and divide 

 by 7 ; result = percentage of CaS0 4 . Enter results as 



Moisture . . . . . . 1 5 -oo 



Organic matter ..... 12*00 



Soluble phosphate . . . . . 18-00 



Equal to Ca 3 (P0 4 ) 2 (28-28) 



Insoluble phosphate . .... 6*oo 

 Sulphate of lime . . . . .41*95 



Alkalis, &c *55 



Sand 6-50 



100 -oo 



233. Dissolved Bones and Guanoes with an Acid 

 Reaction are analysed by one of the above methods with 

 the additional determination o/N. This is best done by the 

 acid method, but should the soda lime be preferred, a difficulty 

 will be met with in the mixing of the pasty material with soda 

 lime. This is overcome as follows : From 1 to 2 grams are 

 weighed out on a watch glass and covered over with about 

 4 grams of gypsum. The watch glass with its contents is then 

 left in a desiccator. In about half-an-hour the substance is 

 removed to a mortar, rinsing out the watch glass with fine sand 

 which has been well ignited. The mass will be now fairly dry, 

 and by adding sand in small quantities at a time, grinding 

 with the pestle after every addition, it will soon become per- 

 fectly powdered. It may then be mixed with soda lime, and 

 proceeded with as described in paragraph 88. 



The following are typical analyses of dissolved bones : 



