AMERICAN INSTITUTE. 283 



I come to ask votes of merits, to Mons. Montigny, who sent it us 

 from Cliina, and to the members, who have carefully cultivated 

 in their departments this precious plant. 



The regular subject was then called up, viz : " The relations of 

 Ammonia to Vegetation." 



Dr. Waterbury oljserved, that when first he commenced the 

 practice of agriculture, he was led to believe that the necessary 

 ammonia would be furnished from the atmosphere. Leached 

 ashes formed the only manure he employed, and yet, without 

 green crops plowed in, or stable manure, he could never obtain 

 good crops. 



There was a close relation betvreen the use of plaster of paris 

 and the growth of plants. Plow did this arise I Farmers said 

 that it stimulated the plants. But plants have no nerves. Lie- 

 big had explained it, by finding that the plaster of paris had 

 become converted into chalk. It is decomposed in the soil into 

 carbonate of lime and sulphate of ammonia. 



If the foecal matter of animals be valuable because of the 

 ammonia, how is the alkali to be fixed? In order to effect this, 

 different plans have been advised. The formation of a compost 

 with earth so as to absord the ammonia, was one expedient. 

 Others are for keeping dung-heaps dry, the field catching the 

 ammonia as it is eliminated by decomposition. Prof. Rose, of 

 Berlin, had shown that ammonia and carbonate would unite in 

 as many as twelve different forms, so that the more the acid is 

 absorbed, the less ammonia is lost in the atmosphere. 



Ammonia, as is known, is a compound of nitrogen and hydro- 

 gen. No one knows how the ammonia in the atmosphere is 

 generated. The quantity of ammonia in the rain-water of the 

 air is an indication of the fertility of the country. In its round 

 of circulation, the ammonia atom may be thus traced. Crude 

 sap becomes elaborated sap, and finally albumen. In its down- 

 ward track of degradation through the animal, the albumen is 

 changed into the substance of muscle, which in turn is changed 

 into the urea of the urine. The power or endurance of a horse 

 is well indicated by the quantity of urea in his urine. This urea 

 again becomes ammonia, to begin again its ascending round in 

 the vegetable. 



