96 HISTORY OF GEINE. 



ammonia; at 383° F. acetic acid. Humic acid was also 

 prepared from the black mould of an old white willow, by 

 a similar process as above. It suffers no change below 302° 

 r., and at 325° it evolves water and acetic acid. Digested 

 with caustic potash, it evolves ammonia. Continuing this 

 digestion for twelve hours, and then precipitating the humic 

 acid, it is found converted into^ulmate of ammonia, with two 

 portions of acid. It is a biulmate of ammonia, similar to 

 that from peat. If digested with carbonate of soda, the 

 product then is biulmate of ammonia, like that from sugar. 

 Soil was treated by Mulder, first, with boiling alcohol, then 

 with water, then with carbonate of soda, and the acids pre- 

 cipitated as usual, by muriatic acid. These precipitates were 

 with difficulty obtained pure. They were repeatedly washed 

 in cold water, dried, and again treated with alcohol, to 

 remove every trace of crenic and apocrenic acid. These 

 being removed, the precipitates were again dried, as in fact 

 were all the products above described at 284° F. They 

 were then analyzed. It is remarkable that all these pro- 

 ducts are ammoniacal combinations. It is a combination, 

 not as a salt, in which case the geine of soil would be at once 

 soluble in water, but a compound of humin and ulmin, or 

 of their acids with ammonia, probably like the compounds 

 of ammonia with sulphates and other salts. The whole may 

 be best presented in a table, and that these natural may be 

 at once compared with the artificial products, these are also 

 included. 



