On a Disease in Elm Trees. 381 



and the outer bark is perforated with innumerable holes, as 

 with a brad -awl. 



But still, I confess, it appears to me, as well from the other 

 affidavits and depositions upon the subject as from my own 

 observation, that the elm trees, in the present case, are visited 

 with a distinct and independent disease ; which I learn was 

 prevalent last summer, and may yet be seen in many other 

 parts of the country where no gas has ever been, and where 

 the Scolytus does not appear to have been noticed. 



In Camberwell Grove the mains were laid close to the 

 trees, on the left-hand side of the road as you ascend, and 

 equally near to all the trees on that side, and yet the elms 

 on the right-hand side, at a distance of thirty feet from the 

 mains, were equally and in the same manner affected, and 

 no other species of tree was thus visited. The disease is 

 thus described by Mr. Lindley, the garden secretary of 

 the Horticultural Society, in his deposition : " The outer 

 or indurated bark of such of the said elm trees as present 

 the unhealthy appearance aforesaid is detached and easily 

 separable from the inner bark thereof, and very considerable 

 quantities have fallen or been stripped off from the said trees. 

 The inner bark exhibits the appearance of considerable extra- 

 vasation of the juices having taken place, thereby giving to 

 the surface thereof an unusually humid appearance, which, in 

 the opinion of the deponent, indicates an approach to putre- 

 faction ; and, in one instance, the extravasation of the juices 

 had become so copious as to flow from the tree in the form of 

 foul putrid matter." Mr. Lindley then proceeds to detail at 

 length the arguments and reasonings upon which he is con- 

 vinced that the disease in question is in no way arising from, 

 or connected with, the gas ; and he makes it clear almost to 

 demonstration, by an illustration of a particular case, that if 

 the trees had really absorbed poisonous or deleterious matter, 

 a general aridity would have been the result, in consequence 

 of which the bark would have adhered more closely than usual 

 to the wood, and no extravasation of the juices and decortic- 

 ation, as in the case of the trees in Camberwell Grove. 1 

 lament that I have not room to copy from his deposition the 

 description of the manner in which the circulation of the sap 

 of the tree takes place, from which he proves that the leaves 

 and the ends of the branches, and not the trunk, would have 

 been the first parts affected, supposing that the gas had exer- 

 cised any specific influence upon the trees. He concludes by 

 quoting from, and referring to, the works of several learned and 

 able writers, who have treated upon these diseases as incident 



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