18 Wisconsin State Horticultural Society. 



set out elms they have set all elms. In our city there is no 

 uniformity. Many of the trees after a few years are worth- 

 less. Every man who comes from the city of New Haven 

 is proud of it, and because of its elms. 



President Smith — Ladies and gentlemen, we must 

 close this discussion and postpone our going to Mr. Lou- 

 don's on account of Professor Armsby who has to go to 

 Madison to night. 



Prof. Armsby — Ladies and gentlemen, the subject as- 

 signed to me by the secretary is a pretty broad one, and as 

 he left me no special instructions, I suppose he left it to my 

 discretion as to the branch I should take up. There are a 

 great many things to be said about fertilizers; a great many 

 ways in which they may be looked at. If I should take up 

 too many things it would take too much time. I wish to 

 give you a very short talk upon simply one aspect of the 

 question, and that is the best way of buying them; and by 

 fertilizers we mean those that are known as commercial fer- 

 tilizers, those that are much more valuable than manures on 

 the farm. Theseare not used, so far as I know, to any great 

 extent in this state at present. I have no doubt that the use 

 of these concentrated fertilizers will rapidly increase. There 

 are all the indications of an increase of demand for them 

 among market gardners and others. The first question is, 

 what do you buy fertilizers for, and what do you want to do 

 with them? There are three things upon which the value 

 of a fertilizer depends — nitrogen, potash and phosphate. 

 I do not need to detain you with any discussion of these 

 substances. These three substances give value to the fertil- 

 izers. Phosphoric acid is contained in them in three forms. 

 "What is called the soluble, the insoluble and a third inter- 

 mediate one which, while it will not dissolve in water, will 

 dissolve in soil more readily than the insoluble. Some of the 

 most common substances furnish these ingredients. The most 

 common sources of nitrogen are three, salt of ammonia, and 

 the various forms of animal sources such as dried blood and 

 the tankage of slaughter-houses. The phosphoric acid of 

 these fertilizers is almost always furnished either in some 

 form of bone or some form of native phosphatic rock such 



