106 
ORIGINAL COMMUNICATIONS. 
which formed a precipitate that assumed a gelatinous as- 
pect. 
The presence of potassa was demonstrated by tartaric acid, 
forming a bitartrate. Nitrate of silver, hydrochlorate of baryta, 
and acetate of lead, caused precipitates perfectly soluble in 
nitric acid. 
B. Experiment No. 1. — A portion of this bark, in a bruised 
state, underwent ebullition in several successive portions of 
water; the decoction possessed but little color, was very muci- 
laginous, frothed considerably upon agitation, was somewhat 
opalescent, and filtered with difficulty. Exposure to the air 
changed the residuum to an ashy-gray color. 
2. The filtered solution was then subjected to the following 
experiments: With iodine in solution, starch was strongly de- 
veloped. Sub-acetate of lead threw down a copious precipitate 
of gum and mucilage. Ferrocyanate of potasssa, tincture of 
galls and salts of iron had no effect. Litmus had no action. 
Oxalate of ammonia produced a slight cloud. 
3. The decoction was evaporated to the consistence of thick 
molasses, which it resembled in color, smell, and adhesiveness. 
A portion of this extract was boiled with caustic potassa in a 
silver vessel, but gave no indication of sulphur. 
4. With another portion of this extract an aqueous solution 
was made, to which sub. acet. plumbi. was added to get rid of 
the mucilaginous matters, the excess of lead thrown down by 
sulphuretted hydrogen, this again driven off by ebullition, and 
ammonia added to the filtered liquid — but with no satisfactory 
results. 
5. Some of this extract again submitted to heat, puffed large- 
ly, and, when dry, was pulverulent ; further heat caused it to 
give out the smell of burnt sugar, and a spongy charcoal was 
left behind. 
C. Experiment No. 1. — Treated some Dittany, finely 
bruised, with cold water by displacement, from which result- 
ed a straw colored limpid liquid, possessing a fainter odor but 
much more acrid taste than that furnished by decoction, leaving 
an impression upon the fauces which remained some time 
