26 
ORIGINAL COMMUNICATIONS. 
alcohol passes off without any sensible odor, but developes the 
strong odor towards the close of the operation. By continu- 
ing the evaporation to dryness, over a gentle heat, their re- 
mains an acrid, bitter, inodorous, resinous extractive, which 
dissolves equally in water or alcohol, attracts moisture, and 
burns with much puffing, but inflaming with difficulty. 
The substance of these bulbs, after being treated by alco- 
hol, contains nothing but mucilage, mixed with a small quan- 
tity of fibrous matter. If small fragments of the fresh bulb 
be steeped in water, they swell up largely, become transpa- 
rent, and preserve their form like gum tragacanth. Upon 
looking through one of these fragments, minute, slender fibres 
will be perceived. Suffered to remain a longer time in water, 
a further absorption will take place, and the whole be resolv- 
ed into very thick mucilage, exhaling the peculiar venomous 
odor, and in which the fibrous portion will form the three or 
four hundredth part of the whole weight. 
According to Guibourt, but in opposition to the opinions 
of several chemists, the recent solid tubers are composed, very 
nearly like all the farinaceous roots, of a large quantity of 
starch, which, examined with the microscope, and colored by 
iodine, is in uniform grains of an ethereal blue, spherical or 
elliptical, and about the size of the large grains of wheat starch. 
This starch does not contain any interior substance soluble in 
cold water, like wheat or potato starch, but is entirely filled 
with a pulpy matter, insoluble in cold, but swelling, and becom- 
ing much divided in boiling water, which, agreeably to the views 
of Mr. G., explains the abundance and great consistence of 
the jelly of salep. The rest of the root is composed of thick 
membranes colored yellow, very small gelatinous-like glo- 
bules, transparent and colorless, and very often needle-like 
points, which disappear upon the slightest addition of nitric 
acid. These last are phosphate of lime, according to the ex- 
periments of Raspail. The prepared salep of commerce, as 
examined by Caventou, was found to be composed of three 
substances, of which the respective quantities might be cited 
