580 TRANSACTIONS OF THE 



I hope every person present, and wlio may read this article, will 

 try the experiment. 



The condensed facts of this new preventive are these : Some 

 years ago, some boys engaged in the field of a farmer in Belgium, 

 amused themselves by inserting peas into the seed potatoes they 

 were set to plant. In due time both peas and potatoes grew to- 

 gether, producing an unusual yield of peas, which being gathered, 

 the potatoes were allowed to ripen, and upon digging proved en- 

 tirely sound, while the same sort in other parts of the field were 

 badly rotten. 



John Jackson, of Leeds, in his letter to The Mercury^ says : 

 " Mr. Joseph Bower, chemist, of Hunslet, had read the account 

 in the papers, and informed me of it. For some time before I 

 had paid a good deal of attention to the subject of the potato dis- 

 ease, but my inquiries had certainly not gone in that direction. 

 Immediately, however, I set to work, to endeavor to find a solu- 

 tion to the new problem. I submitted many samples of diseased 

 potatoes and of sound potatoes to careful chemical analysis, and I 

 invariably found that the diseased potatoes, as compared with the 

 healthy ones, exhibited a marked deficiency of nitrogen and of 

 nitrogenized matter in every instance, and also a great deficiency 

 as compared with the published analysis of the potato, by Liebig 

 and others, made some years before. From that result, then, I 

 Inferred that the potato was set inherently deficient in nitrogen, 

 but being inoculated with a substance intrinsically rich in that ele- 

 ment, as peas are during the mutual decomposition and chemical 

 changes of the two substances in the process of their germination 

 and growth, sufiicient evolution of nitrogen from the pea would 

 take place, and being absorbed by combining with and supplying 

 the deficiency of that element in the potato, communicating, as it 

 were, its equivalent in that way, would counteract its tendency 

 to disease. I then tried the experiment practically. I obtained 

 potatoes of several kinds for sets whole -, and then took peas, 

 Bishop's dwarfs), and inserted four or five (according to the size 

 of the potato), deep in the fleshy part of the set, taking care to 

 avoid the eyes. I then planted them in my garden at Hunslet, in 

 the usual way. Mr. Bower, and several other gentlemen at 



