t^ 



Mr. A. B. Northcote on the Function of Salt 



of the ammonia eliminated during these changes, is a matter, 

 the investigation of which must necessarily be attended with 

 great difficulty ; but with respect to its capabiHty of such ab- 

 sorption, I am informed by my friend Mr. Frideaux, that he 

 has habitually observed that salt mixed with guano retards the 

 exhalation of ammonia from the latter; and he has directed 

 my attention also to some experiments* conducted by M. Barral, 

 one of which proves this point in a remarkable degree. M. Bar- 

 ral exposed to the air for fifteen days, equal weights of guano, 

 and of guano previously mixed with half its weight of salt : the 

 amount of nitrogen in each being determined at the end of that 

 time, he found that the pure guano had lost ll'G per cent, of 

 its nitrogen, whilst that mixed with salt had lost only 5 per cent. 

 Before entering, however, upon the experiments which I have 

 made upon this subject, and which I may here state have exclu- 

 sive reference to the absorption of ammonia, I will give the ana- 

 lyses and table of constituents calculated from them, of three 

 specimens of agricultural salt which I have examined t- 



Table of direct results of Analysis calculated to 100 parts 

 of the diy salt. 



* Edinburgh Quarterly Jourual of Agriculture, April 1855. 



t The three specimens of which the analyses are given were all produced 

 from the Worcestershire brine-springs ; No. I. being from Mr. Corbett's 

 works at Stoke Prior; Nos. II. and III. from Messrs. Clay and Newman's 

 and Mr. Npak's works at Droitwich, respectively. 



