140 BOARD OF AGRICULTURE. 



value. Its whole contained amount of mineral plant-food 

 does not equal in value more than fifty or sixty cents a ton, 

 and the bog-humus in which it is involved is of little value 

 except as an absorbent. 



Now let me answer the question. I think that ashes upon 

 meadows have always answered a very excellent purpose. I 

 should recommend the use of ashes always, if you can procure 

 them. If you cannot obtain ashes, the use of sand is excel- 

 lent. As Mr. Moore has told us, it gives strength to the 

 grass. It probably becomes, in part, soluble, — soluble silica, 

 — and supplies food to the plant. I have found it on my 

 meadows to operate very well. 



Mr. George J. Peterson. I have often thought that we 

 needed an agricultural dictionary. It seems to me, from this 

 discourse, which is one of the most valuable that has been 

 presented to the Board for twenty years, that the doctor is 

 the man to make tluit dictionary. For instance, we would 

 all like to know what nitrogen is. You, gentlemen, all under- 

 stand that nitrogen is a subtile element, but an exceedingly 

 valuable one. 



Dr. Nichols. I suppose there is a great deal of confusion 

 existing in relation to the employment of the word " nitro- 

 gen " in agriculture. Let me see if I cannot show you what 

 is meant by it. Of course, nitrogen is all about us, and forms 

 a very important constituent of air. I have had farmers of 

 considerable intelligence come into my laboratory, and wish 

 to know if I could not furnish them with a bag of nitrogen. 

 Of course they made a mistake. Nitrogen itself is a gaseous 

 body. I suppose the plant must get a portion of nitrogen 

 from the air. I am inclined to think, that, with the common 

 atmosphere, nitrogen is assimilable to a certain extent ; how 

 far, I do not know. But when we speak of "nitrogen," we 

 speak of it in combination with other substances, locked up 

 as it is with various salts, — for instance, in sodium it is locked 

 up with caustic soda, — and it has a certain value in those 

 combinations. The plant, when this is dissolved, seems to 

 have the power of appropriating those molecules of nitrogen, 

 and making them into plants; and it serves a very good pur- 

 pose. I have not cleared up all the points about nitrogen. 

 I can only give the commeroial value of nitrogen as we hnd 



