TRUE OIL OF ORIGANUM. 
167 
the tomato, and the absence of all other acids. Other reagents 
were employed, besides those named; but, as they all produced 
corroborative evidence of the presence of citric acid, to the exclu- 
sion of others, I have not thought it necessary to add their indica- 
tions to the foregoing. 
It now became an interesting question, whether the acid dis- 
covered was wholly free, or in combination with a base. To re- 
solve this problem, I added to the acid juice (2) a solution of tar- 
taric acid in excess, and strongly agitated the mixture. [ A granu- 
lar precipitate was formed, characteristic of potash. Tartrate of 
lime would have redissolved in the excess of tartaric present, and 
would also have disappeared in sal-ammoniac solution, which did 
not occur with the present precipitate. 
Citrate of potash, then, with excess of citric acid, is the salt 
which gives to the tomato its agreeable flavor. 
George Dow (General History of Dichlamydeous Plants, in four 
ponderous volumes, London, 1831) says the esculent tomato was 
cultivated as early as 1596. Can it be possible, that so much time 
has elapsed, and this fruit has been so very generally relished in 
different nations, and yet no one has heretofore been prompted to 
examine into the cause of its palatableness ? 
I have some further observations to make on this plant, and 
especially on its medicinal properties; but they will, perhaps, be 
more appropriate on another occasion. 
Western Lancet, Jan., 1851. 
ON TRUE OIL OF ORIGANUM. 
By Daniel H anbury. 
In a recent number of the Pharmaceutical Transactions*, I 
endeavored to prove that the article sold in this country as the oil 
of origanum is, in reality, the oil of thyme {Thymus vulgaris,) 
under which latter name it is imported from the south of France. 
I further stated, that, so far as my observations extended, true oil 
of origanum was unknown in English commerce. 
* Vide vol. xxii., page 367, American Journ. Pharm. 
