266 STATE HORTICULTURAL SOCIETY. 



that the yellows was due to a lack of necessary food elements in the soil, and 

 cited the four analyses in proof. A remedial treatment based on this theory, 

 and consisting of liberal doses of phosphates aud of sulphate and muriate of 

 potash, was begun at Amherst, by Professor Maynard, in 1878, and the results 

 of this treatment were also offered in proof. 



This treatment was repeated by Professor Penhallow, at Houghton Farm, 

 New York, the results there obtained being embodied in a special report of 

 tthat experiment station, which was published in 1883. 



In 1884, at the request of P. M. Augur, State pomologist, the Connecticut 

 experiment station also made analyses of diseased and healthy peach twigs, 

 from which it appears that the ash of the diseased tissue contained no excess 

 of lime, but an excess of silica and other insoluble matters, and a deficiency 

 of nearly all the other constituents. 



In recent years Professor Penhallow is the one who has insisted most 

 strenuously on the correctness of this soil exhaustion theory, and among 

 practical peach growers who have given more or less sanction to his views may 

 be named H. H. Appleton, Odessa, Del. ; John P. K. Polk, Wilmington, Del. ; 

 Eli Minch, Shiloh, N. J. ; and J. H. Hale, South Glastonbury, Conn. His 

 treatment, as given in a Houghton Farm Bulletin, Series III, Nos. 1 aud 2, 

 and in a more recent communication to the author, consists in the application 

 of 625 pounds per acre of a mixture, by weight, of 1 part of kieserite (crude 

 epsom salts), 6 parts of muriate of potash, and 18 parts of dissolved bone-black 

 (bone-black in sulphuric acid). This to be applied, one-half spring and fall, 

 just before and after leafing; and, if marked evidence of the disease is pres- 

 ent, an additional 2 pounds of muriate of potash must be given to each tree 

 in spring and fall. The orchard must also first be pruned severely, to cut 

 out all tiie noticeably diseased wood. 



If yeach pellows can be cured in this simple manner every peach-grower 

 ought to know it, for hundreds of orchards in New Jersey, Delaware, and 

 Maryland are being ruined, entailing great financial loss. Even if this treat- 

 ment can be depended on as a reasonably certain preventive, it is one of the 

 most important horticultural discoveries of modern times. The fact that the 

 ingredients here supplied in a concentrated soluble form are found naturally 

 in considerable quantity in the ash of healthy peach trees is certainly an 

 argument in their favor. If yellows, therefore, is only synonymous with 

 starvation, the results of this treatment ought to be speedy and unmistakable. 

 Six years have passed since the publication of Dr. Goessman's analyses, and 

 many faithful trials have been made by peach growers. What have been the 

 results? 



When I began my field work, in July, 1887, I had no favorite theory to 

 advance, but gave very careful attention this one, among others, hoping, for 

 the sake of the fruit growers, to be able to confirm it. This I have not been 

 able to do. 



In the first place, there appears to be an error of logic in deriving conclu- 

 sions from premises. In the diseased tissues Dr. (ioessman found a deficiency 

 of potash, and with this fact for one premise, and for the other the knowl- 

 edge that potash is procured by the plant only from the earth, he aud Pro- 

 fessor Penhallow assumed a lack of this substance in the soil. Even assum- 

 ing a constant deficiency of this sort in diseased trees, the conclusion which 

 they reached by no means logically follows, any more than it follows that 

 the leanness of a consumptive or a dyspeptic is attributable to a want of 

 appetite or of sufficient food. If in diseased tissues there is a constant 



