such is the case it should be preserved in a cool cellar. Most of the
samples from the gas-heated shelves of the druggists' shops, are as much
like essence of turpentine, to the smell, as that of lemons; rancid oil
of lemons may, in a great measure, be purified by agitation with warm
water and final decantation. When new and good, lemon otto may be freely
used in combination with rosemary, cloves, and caraway, for perfuming
powders for the nursery. From its rapid oxidation, it should not be used
for perfuming grease, as it assists rather than otherwise all fats to
turn rancid; hence pomatums so perfumed will not keep well. In the
manufacture of other compound perfumes, it should be dissolved in
spirit, in the proportion of six to eight ounces of oil to one gallon of
spirit. There is a large consumption of otto of lemons in the
manufacture of Eau de Cologne; that Farina uses it is easily discovered
by adding a few drops of Liq. Ammoniæ fort. to half an ounce of his Eau
de Cologne, the smell of the lemon is thereby brought out in a
remarkable manner.

Perhaps it is not out of place here to remark, that in attempts to
discover the composition of certain perfumes, we are greatly assisted by
the use of strong Liq. Ammoniæ. Certain of the essential oils combining
with the Ammonia, allow those which do not do so, if present in the
compound, to be smelt.

LEMON GRASS.--According to Pereira, the otto in the market
under this name is derived from the _Andropogon schoenanthus_ a
species of grass which grows abundantly in India. It is cultivated to a
large extent in Ceylon and in the Moluccas purposely for the otto, which
from the plant is easily procured by distillation. Lemon grass otto, or,
as it is sometimes called, oil of verbena, on account of its similarity
of odor to that favorite plant, is imported into this country in old