114 ULMACE.E. 



it is unnecessary to enumerate, these having already been 

 described by Evelyn and subsequent authors. Its dura- 

 bility under water, as well as the straightness and great 

 length of its stem, qualifies it for making the keels of large 

 ships, for which purpose it sells at a very high price. It 

 was, alsp, before the general introduction of cast-iron pipes, 

 almost exclusively used for the conveyance of water in all 

 water- works in and about London and other towns; and 

 as further uses to which it seems applicable from its 

 durable qualities, may be suggested, the making of sleepers 

 upon iron railways, where timber is selected for this pur- 

 pose, and for the wooden pavement lately introduced, 

 should it be found to succeed in the trials instituted in 

 some of the crowded streets of the metropolis. 



Upon the whole we consider that the English Elm 

 has the advantage over the Scotch, or Wych Elm ; for 

 any inferiority in regard to longitudinal toughness in the 

 first, is amply compensated by its greater lateral adhesion, 

 its durability when exposed to weather, its superior size, 

 greater length, and straightness of trunk. 



The Elm is subject to the attack of several insects, 

 among which the Scolytus destructor, a beetle belonging 

 to the family Bostricidce, Leach, was considered, some years 

 ago, as by far the most formidable and destructive, as 

 to its ravages in the larva state were attributed the decay 

 and subsequent death of the finest Elms in the vicinity 

 of London, particularly those in St. James' and Hyde 

 Parks. Subsequent observations on the economy and ha- 

 bits of this insect have, however, shown that the Scolytus 

 is not always, indeed perhaps but seldom, the proximate 

 cause of decay, and that the trees are not attacked by 

 the pregnant females for the purpose of depositing their 

 eggs beneath the bark, until they have become injured 



