1891.] PUBLIC DOCUMENT — No. 4. 27 



with that , that I do not see how we can very well regulate 

 that matter. Even allowing that there ought to be more 

 carbonic acid in the atmosphere than there is, how are you 

 going to get it there or keep it there ? The wind will blow it 

 away. It has been thoroughly demonstrated that plants do 

 not derive their carbonic acid through their roots. If we 

 could control it, it would be all right ; but, suppose we 

 should get a little more carbonic acid over our com field, 

 our neighbor will get it, if he lives on the windward side. 



Mr. Hersey. It seems to me that if we fill our soil at no 

 cost with carbonic acid gas, a considerable portion of it 

 would naturally escape to the air and surround the plants, 

 and thus the plants would take up what they needed ; and, 

 if there was any left, it would be all well enough for the 

 neighbors to have it. 



Professor Whitcher. If there was any possibility of 

 appreciably increasing the amount of carbonic acid in the 

 atmosphere, the increased consumption of coal that is going 

 on at present ought to have had an effect before now ; and 

 yet the results of analyses show that the carbonic acid in the 

 atmosphere remains practically unchanged. Of course we 

 cannot tell absolutely, because the methods of determining 

 the amount of carbonic acid in the atmosphere employed by 

 the early experimenters may have been faulty ; but I think 

 there is no belief among scientific men that the amount of 

 carbonic acid is increasing. 



Mr. E. 13. Lynde of West Brookfield. My neighbor sitting 

 here by my side, and I, have been discussing the question of 

 manure. He practices spreading his manure on his grass 

 ground and ploughing it under ; I do not. My manure all 

 drops into the cellar, and never freezes ; but, notwithstanding 

 that it can remain there until spring and never freeze, I 

 carry it out as fast as it is made, no matter if the snow is 

 two feet deep. I have never practiced ploughing manure 

 under upon grass land. It seems to me that there would be 

 likely to be a loss if it is treated in that way. 



Question. What is the character of your soil? 



Mr. Lynde. A sandy loam. 



Secretary Sessions. I wish Professor Whitcher would 

 touch upon the matter of leaching, in answering that question. 



