VALUE OF MANURES. 217 



posed to the experiments wliicli lie (Mr. Karkeek) had placed 

 before them that day, and it was also opposed to Liebig-'s 

 previous teaching*. They mig'ht rely upon it that the inor- 

 ganic elements were of very little use in a soil as food for 

 plants, without a corresponding" supply of the organic. The 

 reason that guano answered so well was, because it contained 

 (like farm-yard dung) all the elements which plants require ; 

 and putting either into the earth restored those substances 

 which the plants abstract from it, and which are necessary 

 to their growth. For the turnip crop next season, he would 

 recommend them to use a mixture of superphosphate of lime 

 and guano, in preference to either of those manures singly, 

 which he had every reason to believe would be found to be a 

 useful and economical manure, not only for txu'nips, but 

 for grain crops generally. Another advantage derived from 

 the mixing of these manures was, that the superphosphate 

 fixes the volatile parts of the giiano, and prevents its dissi- 

 pation into the atmosphere, which loss must othei'wise ensue 

 when so small a cpiantity as 2 cwt. or 3 cwt. is distributed 

 over an acre of ground as a top-dressing for corn or grass, 

 particularly in dry weather. Some of the guanos are more 

 evaporable in the atmosphere at common temperatures than 

 others. The South American is less volatile than that from 

 Ichaboe and other African localities, which, under circum- 

 stances of exposure, should be either mixed with a substance 

 that would lessen its volatility, or be quicldy covered up 

 in the soil. 



Agricultural Gazette, Jan. 23, 1847. 



