252 AMERICAN MANURES. 



ington manufacturers may be more honest, and 

 make a better article than their Philadelphia 

 brethren it is almost impossible that they 

 could make a worse. The use of these certifi- 

 cates by the Philadelphia Company is literally 

 stealing the thunder of the excreta of Wash- 

 ington. 



METHODS OF ANALYSIS. 



The methods of analysis employed to deter- 

 mine the amount of nitrogen, actual ammonia, 

 and potash, and of phosphoric acid in the several 

 manures, of which analyses are given in this 

 chapter, are of too intricate a nature to be un- 

 derstood by the general reader. Hence we state 

 the methods only in general terms, with such 

 remarks and particulars as will enable profes- 

 sional chemists, into whose hands our work may 

 fall, to estimate the carefulness with which they 

 have been made. 



METHOD FOR TOTAL NITROGEN. 



From about 30 grammes of the finely pul- 

 verized and intimately mixed substance 1 to 

 2 grammes were taken for analysis, which was 

 made according to Varrentrapp and Wills' me- 

 thod. We remark, that the actual amount of 

 Nitrogen was calculated from the actual amount 

 of metallic platinum obtained, and not from the 



