FORTY-FIRST ANNUAL REPORT. 119 



Mr. Farrand — That depends entirely on whether the solution is n 

 perfect one or whether there is any sediment in it. If so, crystallization 

 will take place. It should be air-tight, and even then if there is foreign 

 matter there will be some crystallization. The freezing ^\i\\ uot hurt 

 it if it is left perfectly quiet until it has thawed out. This may burst 

 the barrel, and you may lose some of the liquid, but the strength of the 

 material will not be lost simply by freezing. 



A Member — Is there anything to be gained by using an excess of 

 lime in our sprays? 



Answer — I have a neighbor that puts in an excess of lime, the object 

 being that he may the better see where he has been. I do not think there 

 is any advantage in it so far as the solution is concerned. 



A Member — I would like to know if arsenate of lead is affected by 

 freezing? 



Answer — With the exception that it does not mix up as readil,y, there 

 is no trouble — the poisonous property is not destroyed. Freezing will 

 make it granulate, and it is rather hard to dissolve these hard granules. 



A Member — That is my experience — -it took a long time to pulverize 

 up these granulated particles of the arsenate of lead. 



COMMERCIAL FERTILIZERS. 



PROP. A. J. PATTEN, MICHIGAN AGRICULTURAL COLLEGE. 



It is safe to say that more money has been spent unwisely or blindly 

 upon commercial fertilizers than upon any other commodity with which 

 the farmer has to do. 



If I were to ask each person who uses commercial fertilizers, in this 

 audience, his reason for choosing any certain brand in preference to 

 the others at his command, I wonder how manv could give a real sound 

 explanation based upon his observation of the soil and crop. 



Now the reason for this is, to my mind, due to our ignorance of the 

 effects of fertilizers upon the soil. For years, in fact ever since the 

 famous German chemist, Liebig, pronounced his theory of fertilization, 

 commercial fertilizers have been looked upon simply as a means of sup- 

 plying plant food to the soil to compensate for that removed by crops. 

 Many of you will remember what a volume of criticism was heaped upon 

 the Bureau of Soils of the V. S. Department of Agriculture, about 

 ten years ago, when they first intimated that fertilizers may have other 

 functions in the soil. 



Todav, however, scientific men the countrv over are more and more 

 inclining to this belief. 



In support of this theory, let me bring the following facts to your 

 attention. The average fertilizer sold in Michigan has approximately 

 the following formula : 



•*? 



1.23% Nitrogen 



8.00% available Phosphoric acid 



3.00% Potash 



