86 ESSEX SOCIETY. 



amount of this noxious odor, this ammonia which it contains. 

 This gas commonly known as hartshorn, is an exceedingly 

 powerful stimulant. Nor will it appear unimportant, when we 

 bear in mind that two and one quarter pounds of this ammonia, 

 lost by fermentation, is equal to the loss of one hundred and 

 fifty pounds of grass or grain. Scientific men will say that 

 this gas is taken up in the atmosphere by the rain, and descends 

 with the rain to fertilize the earth. This is very true. This 

 ammonia, this stimulating odor, so valuable, so indispensable to 

 the earth, is not lost forever, when it flies away into the air. 

 But does not the shrewd farmer perceive that as much of this 

 as he allows to escape from his own lands, by neglect, falls 

 upon, and improves the fields of his neighbor as much, and per- 

 haps more than his own ? Is it not evident, that by saving all 

 that he can, and by receiving whatever the genial rain brings 

 with it, he gets a double benefit ? 



If the effect of plaster is such as we have described, no one 

 can fail to see how important are the functions it may be made 

 to perform. But it also adds a certain amount of lime and sul- 

 phur to the earth. It is composed of these substances for the 

 most part, and hence called by chemists, sulphate of lime. We 

 shall have occasion to speak of its use in connection with other 

 manures, when we speak of the compost heap. We now al- 

 lude to its use by itself, as a top dressing. 



On some soils it is not so satisfactory as on others. But our 

 pastures are many of them covered with the white honeysuckle. 

 These might be called clover lands. On all clover lands, 

 whether reserved for pasture or mowing, plaster has a most 

 wonderful influence. No other manure produces such an enor- 

 mous increase of vegetable growth, in proportion to the quan- 

 tity applied. Most manures require to be used in quantities 

 far exceeding the bulk of the expected increase. Not so with 

 gypsum. A bushel, or two bushels to the acre, have been 

 known to double the crop, and to add more than twenty times 

 its own weight to it. Even greater results have followed. For 

 if we may believe one of the most distinguished French chem- 

 ists,* every pound of nitrogen which we add to the grass, in- 



* Boussingault, Ann. de Ch. cl cle Phys., t. 43, p. 243. 



