No. 7. DEPARTMENT OF AGRICUL.TTJRB. 215 



different kinds of weeds. They may be common fox-tail or fall grass. 

 I got a sample last winter that coutained over fifty per cent, of fox- 

 tail, and fall grass that was brought to me as good quality of seed. 

 The farmer who grew it of course thought it was good. 



As for the germination test, the farmer can do that just as well 

 as we can do it at the experiment station and it is just as sat- 

 isfactory. It does not take any very special apparatus, either. 

 Take simpl}' two dinner plates and a strip of canton flannel about 

 that long (indicating) and moisten that canton flannel thoroughly 

 and squeeze it out so that it does not drip and put down two thick- 

 nesses of it at the bottom of the plate and upon that we put our seed. 

 Now there is one thing which I would mention as a precaution; 

 never make a germination test without knowing exactly how many 

 seeds you put in. If you do, you don't know in such a case whether 

 ten per cent, germinate, or whether you have ninety-nine per cent. 



A Member: If I find that by examination under the magnifying 

 glass, would it be absolutely necessary for me to know the botanical 

 names of these weeds? 



PROF. DUVEL: No, it would not; you would take it for granted 

 that they were bad seeds anyhow. 



The CHAIR: The next subject on the program is, "Domestic 

 Science, or Farm Homes," which was to have been presented to us 

 by Mrs. T. E. Orr, of Beaver, Pa., but on account of her illness we 

 shall be obliged to dispense with that topic, and we will pass on 

 to the next number on the program. No. 3, which is entitled "Ac- 

 cumulation of Soil Nitrogen." We shall have the pleasure of list- 

 ening to Prof. J. W. Harshberger of the University of Pennsylvania 

 who will now address us upon that topic. It gives me pleasure to 

 introduce to you Prof. Harshberger. 



PROF. HARSHBERGER: Mr. Chairman, and Ladies and Gentle- 

 men: I have been asked to speak on the accumulation of soil nitro- 

 gen. Before speaking on that subject, I would like to say a few 

 words about how the nitrogen is lost from the soil. Perhaps the 

 most important way is the drainage from the upper layers of the soil 

 down into the lower layers, down into the sub-soil. Now this 

 takes place more rapidly in autumn and in the winter months. The 

 nitrogen is lost and the other ingredients are lost more or less 

 rapidly during the summer and winter months. 



Now it is very important to grow a catch crop, some crop that 

 will hold that soil nitrogen. 



Prof. Harshberger then read the following paper: 



THE ACCUMULATION OF SOIL NITROGEN. 



By PROF. J. W. HARSHBERGER, University of Penvsylvania, Philadelphia. 



It is important before considering the accumulation of soil nitro- 

 gen, to briefly state how the soil may lose this valuable chemical sub- 

 stance. The nitrogen in the form of ammonia gas may be diffused 



