96 WISCONSIN AGRICULTURE. 



since tlie sulphate of lime is sufficiently soluble in water, the 

 process is simple, whereby it is brought into contact with the 

 innumerable little mouths of the branching rootlets, 



2d, It acts as a stimulant, quickening the growth of the 

 plant, and developing it more rapidly than almost any other 

 sulphate; avoiding, too, the excessive action to which all the 

 more soluble salts, such as sulphate of soda, sulphate of potash, 

 sulphate of magnesia, &c. are liable. Requiring 468 times its 

 weight of cold water to dissolve it, the amount held in solution 

 and liable to enter the circulation is of course materially dimin- 

 ished ; so that while the other salts referred to, if furnished in 

 excess, are too rapid in their action, and too intense, producing 

 a dry, parched condition, and even death, the slow and moder- 

 ate action of gypsum is uniform, health giving and constant, so 

 long as furnished to the soil. 



3d, Gypsum absorbs moisture from the atmosphere, yielding 

 it to the roots of the plant, and in this way prevents ofttimes the 

 disastrous effects of drought, 



4th, It absorbs carbonate of ammonia from the air and from 

 rain water and, decomposing it, so as to form carbonate of lime 

 and sulphate of ammonia — the two acids having exchanged 

 bases — operates to secure a much larger amount of this es- 

 sential food than would otherwise be available. Experiments 

 have shown for instance, that 1 00 lbs. ©f plaster is able to fix 

 20 lbs. of ammonia, which, containing 16 1-4 lbs. of all-impor- 

 tant nitrogen sufficiently indicates its value, if applied simply 

 with reference to that one element. 



rth. It operates effectively to facilitate the decomposition of 

 vegetable mould, and is also invaluable as a means of retaining 

 for the uses of the soil, the gaseous elements thereby evolved. 



Finally, it is probable that its powerful acid and active base 

 may fulfill some important office in the way of decomposing the 

 more complex minerals. 



The plants to which gypsum is most advantageous are clover, 

 lucerne, sainfoin, beans, peas, vetches, most of the grasses, In- 

 dian corn, rye, buckwheat, potatoes, and hemp. It is also 

 highly recommended by some for the vine and a variety of fruit- 



