404 Difeafed Elms.—New Pneumatic Apparatus. 
more than five or fix feet above it. This difeafe, arifing fromt 
a fuper’bundance of fap, differs from another difeafe of the 
elm defcribed in the Journal d’ Hifioire Naturelle* for the 
vear 1789, in this cireumftance, that the liquor, when 
expofed to the atmofphere, foon acquires the confiftence of 
a.gum, and has a very faccharine tafte. 
To cure the trees attacked, C. Boucher pierced each of 
them with an auger, which he inferted in the ulcer itfelf, 
and then fitted to the hole a tube which penetrated to the 
depth of 1°10 inches. Sound trees pierced in this manner 
yield no liquor; but thofe which are difeafed-give a more 
abundant quantity, in proportion to the ferenity of the wea- 
ther, and as the wound is more expofed to the fouth. This 
effet is fufpended by ftormy weather and. high wind, He 
obferved that at the end of two or three days the efflux of the 
fap ceafed, and that the wound dried up and was healed. 
This, therefore, is a fimple and eafy method of radically 
curing elms attacked with this difeafe. It is probable that 
. the fame procefs applied to other vegetables, and particularly, 
to fome fruit-trees, would produce a like effect. Pliny, Co- 
lumella, and Palladius, mention the fame means as haying 
been employed by the ancients, but it has not been before 
practifed for many years. 
C. Boucher has completed his obfervations on the elm, 
and proved that this tree is not an exotic, as fome authors 
have advanced. The fiudy of the ancients has proved to him 
that it exifted in Europe in the remoteft periods, and very 
eyident remains of it have been found in old mofles, 
The analyfis which C. Boucher made of the fap of the elm 
fhewed that it contains a pretty large quantity of the acetite 
of pot-afh, a little of the acetite of lime, a certain quantity of 
vegetable matier or faccharine mucus, and a pretty large 
quantity of the muriat of lime. There exift in it, alfo, flight 
traces of the fulphat and muriat of pot-afh. This is nearly 
the fame analyfis as that before announced by C. Vauquelin, 
NEW PNEUMATIC APPARATUS. 
Mr. H, W. Pepys jun. has conftructed a mercurial ex- 
haufter on the principle of the Torricellian yacuum. The 
* No. 5 and 6, ; 
inventor 
