Experiments on Manioc. 
139 
appeared to be a mixture principally formed: 1st, of an acrid, 
bitter principle ; 2d, of acetic acid ; 3d, of vegetable osma- 
zome : (or what I have termed such,) 4th, of a trace of sugar* 
The whitish deposit AA, after the washing with alcohol, 
was dried at 100° C, when it became pulverulent ; it was 
then dissolved in tepid, distilled water and filtered, (there 
was a very small residuum of insoluble phosphate of lime;) 
the solution was limpid, without any sensible colour or taste ; 
when treated with reagents it gave no indication of free 
acid; the oxalate of ammonia formed a slight white precipi- 
tate in a short time. Caustic soda afforded a gelatinous 
white precipitate. Ammonia a flocculent one. Phosphate of 
soda produced a turbidness, which became more evident on 
the addition of ammonia. The acetate of lead, and nitrate 
of silver produced only a slight turbidness. Corrosive subli- 
mate, proto-nitrate of mercury, and the red oxide of the same 
metal gave no indications of the presence of a formiate. Al- 
cohol caused a tolerably large precipitate. Muriate of ba- 
rytes gave a sensible deposit. 
The solution evaporated by a gentle heat, afforded a neu- 
tral, brilliant, white crystalline salt, slightly efflorescent when 
exposed to the air. This salt, when calcined in a platina 
crucible, was decomposed, giving out an odour of burnt 
bread : after a long calcination there was a white residue 
which was found to be magnesia ; it formed about thirty- 
eight to forty per cent, of the salt calcined. 
Finally, a portion of the organic salt having afforded a 
white precipitate with muriate of barytes, I washed this 
carefully, and by means of diluted sulphuric acid, obtained 
some small needle like crystals, which were soluble in alco- 
hol. I am of opinion that this salt, contained a peculiar or- 
ganic acid, but the quantity was too small to determine the 
fact with certainty ; I have termed it manihotic acid. 
From the above experiments, it appears that the juice of 
the bitter manioc examined by me, was composed of : 
1st Hydrocyanic acid, or at least of a volatile principle 
capable of giving birth to it. 
