108 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
The Schleime give on oxidation with H N O; oxalic acid, but no muci¢ 
acid. 
The Gumimi are never colored blue by iodine or iodine and acids. 
The Gummi give, on oxidation, with H NO, mucie acid. 
The two groups, therefore, although so similar in exterior appearance, 
are easily distinguished by these striking characteristics. 
One other peculiarity may be added that, as far as has been investi- 
gated, the Schleime possess no optical activity, while the gums, as arule, 
are quite the reverse. 
The gum which has been extracted from the sorghum molasses is 
plainly to be classed, from its reactions and characteristics, among the 
vegetable mucilages, although it agrees with no hitherto-known member 
of that class. It gives oxalic acid and no mucie acid on oxidation, is 
colored blue by alcoholic iodine and hydrochloric acid, and is optically 
inactive. 
Its extraction and preparation in a pure state was carried out as fol- 
lows: 500 grams of the molasses were dissolved in a half litre of water, 
and to this sufficient 95 per cent. alcohol added to make the resulting 
liquid 80 per cent. alcohol. This caused a precipitation of the gum, 
while the sugar and much coloring matter remained in solution. The 
precipitated gum was washed with 80 per cent. aleohol by decantation 
until the supernatant liquid showed no coloration. The gum, after the 
evaporation of as much as possible of the adhering alcohol, was dis- 
solved in a little water, and the solution, which was of inky blackness, 
warmed for a short time with purified bone-black, was filtered through a 
hot ribbed filter. The resulting filtrate was of a straw-yellow color, and 
on precipitation by alcohol gave a flocculent snow-white gum, which was 
washed alternately by 80 per cent. alcohol, 95 per cent., and absolute 
alcohol, and then on a cloth filter with absolute aleohol and ether. The 
first attempt to dry the gum, on removing it from the filter, was a fail- 
ure. Over sulphuric acid it shrunk up to a gummy, black, oxidized mass 
which was striking in comparison to the snowy whiteness of the original 
substance. It was found necessary to wash very thoroughly with abso- 
Jute alcohol and ether on the Bunsen pump, and then to dry rapidly in 
a stream of CO, at common temperatures, breaking up the lumps which 
formed from time to time. 
The gum so prepared is a white powder, easily oxidizing on expo- 
sure to the air and turning black. It is somewhat deliquescent. Under 
80 per cent. aleohol it may be preserved indefinitely as a snow-white 
substance. In aqueous solution it separates on standing, a thick scum 
or skin forming on the surface. This scum is not colored in any way by 
iodine, and appears to be some decomposition product of the original sub- 
stance into a true gum, like tragacanth. Such adecomposition has been 
suspected in other vegetable mucilages. 
Owing to the difficulty of obtaining the gum dry in a condition fit for 
analysis, no combustion has been made. It contains a small amount of 
ash. Below are some of its reactions in aqueous solution: 
C, H, O Precipitates flocculent. 
NaOH Precipitates flocculent. 
HCl Clears up a turbid solution. 
Pb (C, H3 Oy), Heavy precip. 
Pb, O, (C2 Hs Ov), Light precip. 
HNO, Oxidized to (COO H), 
He, Cl, N yas 
Hg Cl, ; oO precip. 
Tannie acid No precip. 
