216 [Senate 



A ton of night-soil yields 6 pounds 7 ounces of potash. 



Here we see that guano still vastly exceeds even night-soil in these 

 important requisites to fertility ; although the latter possesses a very 

 striking superiority in composition over common manure. We ac- 

 cordingly find in practice, that the comparative value of these diffe- 

 rent manures is very nearly the same that analysis indicates, when 

 the average of experiment is taken. 



There are many other substances which chemistry points out as 

 valuable for manure, which are found useful in practice. Many of 

 these, however, if used singly, or mixed with only one or two others^ 

 often give uncertain results, frequently prove failures, and some- 

 times are a positive injury. Sulphate of ammonia, nitrate of soda, 

 sulphate of lime, silicate of potash and other salts have been knowr^ 

 to produce extraordinary growth ; but in other cases were valueless- 

 So many causes control their action, that this uncertainty must con- 

 tinue to exist. The soil may be already supplied with them ; drought 

 may derange entirely their action ; and ather influences now unknown 

 may produce a similar result. 



Common barn-yard and stable manure, though not so powerful y 

 appears to be more universally beneficial than any other from the 

 certainty of its operation. This certainty is dependent on the great 

 number of its ingredients. It contains a large portion of decaying^ 

 vegetable derived from the pulverized hay consumed by the animal ; 

 it is rich in ammonia and other animal matters, resulting from the 

 secretions ; and it contains many salts derived from both these sour- 

 ces. Poudrette possesses nearly the same advantages ; and guano, 

 from its great quantity of animal matter and enriching salts, rarely 

 fails if properly applied. With single substances, however, there is 

 great uncertainty, until experiment points the way. 



Wheat was found by H. Davy to contain more nitrate of potash 

 than any other farm product ; yet the Author of British Husbandry 



London Ag. Gazette. 



