DISEASES. 183 



rietics of fruit, the spurs and young wood blight or cank- 

 er, and cease to be fruitful for several years 



" If these discoveries and analogies establish, with any 

 degree of certainty, the hypothesis of the cryptogamous 

 origin of the pear tree blight, we have made important 

 progress in laying down true indications for its cure or 

 prevention. Among the means suggested for effecting 

 that end, certain combinations of iron have already been 

 named. The authority for such practice is founded on the 

 following facts: 



" 1. It is a popular belief that iron exerts a favorable 

 influence over the health of fruit trees. Hence arises the 

 practice of driving nails into the body of such trees, and 

 loading their limbs with scraps of iron. Both the be- 

 lief and the practice may be visionary, yet in such in- 

 stances of popular belief, investigation usually discovers 

 them to be founded on some shadow of truth. 



" 2. An intelligent and observing gentleman of Cleve- 

 land informs me that he prevents the curl of the peach leaf 

 by depositing in the earth, about the bodies of the trees, 

 fragments of rusty stove pipe and worthless pieces of iron. 



" 3. Twenty-four years since I called the attention of 

 the public to the isolated fact, without reference to any 

 theory, that a large pear tree in C.olumbiana county, Ohio, 

 with its body surrounded with many wagon loads of boul- 

 ders, scoria, scales of iron and accumulations from a black- 

 smith shop, retained its health, vigor, and fruitfulness, 

 while all other pear trees in that region of country had 

 either died, or were suffering from blight. Vide New 

 England Farmer, December 3, 1840, page 153. At this 

 late dav this tree still continues healthy. 



