586 



Transactions of the American Institute. 



Wheat 



Barley 



Oats 



Rye 



Indian corn.. 



Rice 



Beans 



Peas 



Wheat straw- 

 Barley straw. 

 Oat straw. . . 

 Rye straw . . 

 Maize straw. 

 Rice straw... 

 Bean straw . . 

 Pea straw . . . 

 Red clover.. . 

 Potatoes .... 



Turnips 



Beets 



Cabbage 



Potato tops . . 

 Turnip tops . 



Potash 



and 



Soda. 



33 

 22 

 26 

 34 

 33 

 30 

 44 

 44 

 13 



7 

 29 

 18 

 35 

 14 

 55 



5 

 36 

 57 

 47 

 56 

 32 

 44 

 34 



Lime. 



3 

 3 

 6 

 5 

 1 

 1 

 6 

 5 

 7 



10 

 8 

 9 

 8 



20 

 55 

 33 



2 

 14 



9 

 21 

 17 

 23 



Magne- 



12 



7 

 10 

 10 

 16 

 12 



Phos- 

 phoric 

 Acid. 



50 



39 



44 



50 



45 



53 



38 



33 



3 



3 



3 



4 



17 



1 



7 



5 



8 



13 



12 



8 

 9 



Sulphuric 

 Acid. 



0.25 

 0.10 

 11 

 1 

 3 



4 

 1 



7 



3 



14 

 14 



2 

 22 



7 

 13 



Silica. 



1 



27 



3 



0.4 



1 



3 



1 



0.51 

 65 

 71 

 48 

 65 

 28 

 74 



7 

 20 



7 



4 



8 

 10 



0.74 



4 



1 



It appears that some plants constantly demand more lime, others 

 more magnesia. The effect of the sulphate employed, therefore, 

 depends conjointly upon the composition of the soil, the plants to 

 ■which they are applied, and the manner of their application; also 

 much upon the moisture of the soil and the dryness of the season. 



Liebig says, in Organic Chemistry applied to Agriculture, p. 86, 

 that " the striking fertility of a meadow on which gypsum has 

 been strewed, depends only on its fixing in the soil the ammonia 

 of the atmosphere, which would otherwise be volatilized with the 

 water which evaporates." 



The specific action of gypsum has since been studied in detail 

 by the peers of Prof. Liebig, and his theory, I think, is generally 

 considered as unsatisfactory. 



Johnson, in his Lectures on Agricultural Chemistry and Geology, 

 page 83, says: Supposing the gypsum to meet with a sufficient 

 supply of ammonia in the soil, and that it exercises its full influ- 

 ence, one hundred pounds of common unburnt gypsum will fix or 

 form sulphate, with nearly twenty pounds of ammonia, containing 

 sixteen and a half pounds of nitrogen. One hundred weight, 

 therefore (one hundred and twelve pounds), of gypsum -^ill form 



