on a Substance possessing the Properties of Tannin. 303 
and that the camphor is precipitated unchanged from this solu- 
tion by water. These facts, however, only relate to a certain 
period of the operation, for if this be long continued, other 
effects are produced, which I shall now describe. 
A. To one hundred grains of pure camphor put into a small 
glass alembic, one ounce of concentrated sulphuric acid was 
added. The camphor immediately became yellow, and gra- 
dually dissolved, during which, the acid progressively changed 
to brownish-red, and afterwards to brown. At this period, 
scarcely any sulphureous acid was evolved, but in about one 
hour the liquid became blackish-brown ; much sulphureous 
acid gas was then produced, and continued to increase during 
four hours, when the whole appeared like a thick black liquid, 
at which period not any odour or appearance of camphor could 
be perceived, but only that of the sulphureous acid. After two 
days, during which time the alembic had not been heated, there 
did not appear any alteration, unless that the production of 
sulphureous gas was much diminished. The alembic was then 
placed in a sand-bath moderately warm, by which, more of the 
sulphureous gas was obtained, but this also soon began to 
abate. After the lapse of two other days, I added gradually 
six ounces of cold water, by which the liquid was changed to 
reddish-brown, a considerable coagulum of the same colour 
subsided, the odour of sulphureous gas, which in some measure 
had still prevailed, was immediately annulled, and was suc- 
ceeded by one which resembled a mixture of oils of lavender 
and peppermint. 
The whole was then subjected to gradual distillation, 
during which, the water came over strongly impregnated with 
the odour abovementioned, accompanied by a yellowish oil 
