216 
INNER BARK OF THE ELDER TREE. 
colour, had an acid reaction, and left a brown transparent 
hygroscopic extract, soluble for the greater part, in water. 
The tannic acid contained in it was precipitated by a solu- 
tion of acetate of lead, the excess of lead removed by sul- 
phuretted hydrogen, the liquid filtered and evaporated. In 
this extract grape-sugar was detected by the potash and 
copper test, and in the ash carbonate of potash. To deter- 
mine the acid combined with the potash, the lead precipitate 
was boiled with water and filtered hot, when, on cooling, 
crystals of malate of lead separated. The portion of the al- 
coholic extract insoluble in water contained the above-de- 
scribed mixture of resin and fat. 
The cold infusion of the bark was of a light brown colour, 
tasteless, and yielded on evaporation a transparent light 
brown mass, which on treatment with boiling alcohol be- 
came nearly colourless. It dissolved in a little water to a 
colourless liquid, which exhibited the reactions of Liebig's 
mucilaginous gum. It left on combustion a small quantity 
of carbonate of lime, which was probably contained in the 
plant as malate of lime. The extract remaining after evapo- 
ration of the alcoholic solution had a bitter taste, and gave 
precipitates with acetate of lead, nitrate of mercury and 
silver. 
The extract obtained with dilute muriatic acid was red- 
dish-bro wn : it was evaporated in the water-bath to the con- 
sistence of thin honey, and alcohol added to it, which pre- 
cipitated brown mucilaginous flakes. These, after being; 
well-washed with alcohol, were tasteless, and behaved pre- 
cisely like the artificial gum which is formed on treating 
amylaceous plants with muriatic acid. Evaporated to dry- 
ness and extracted with water, the alcoholic solution, which 
contained some tannic acid, deposited a sediment of extrac- 
tive. The ash of the muriatic extract consisted of chloride 
of calcium, sulphate and phosphate of lime, magnesia and 
chloride of potassium. 
The alkaline decoction of the bark was evaporated in the 
