By the distillation of the whole plant or only the stalk and the leaves, a small quantity of oil is obtained, which is rich in camphor, and is there called oil of spike.  Pure oil of lavender should have a specific gravity from .876 to .880, and be completely soluble in five parts of alcohol of a specific gravity of .894.  A greater specific gravity shows that it is mixed with oil of spike; and a less solubility, that it contains oil of turpentine.

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DIFFERENT ORANGE-FLOWER WATERS FOUND IN COMMERCE

BY M. LEGUAY.

There are three sorts of orange-flower waters found in commerce.  The first is distilled from the flowers; the second is made with distilled water and neroli; and the third is distilled from the leaves, the stems, and the young unripe fruit of the orange tree.  The first may be easily distinguished by the addition of a few drops of sulphuric acid to some of the water in a tube; a fine rose color is almost immediately produced.  The second also gives the same color when it is freshly prepared; but after a certain time, two or three months at the farthest, this color is no longer produced, and the aroma disappears completely.  The third is not discolored by the addition of the sulphuric acid; it has scarcely any odor, and that rather an odor of the lemon plant than of orange-flowers.—­Bulletin de la Societe Pharmaceutique d’Indre et Loire.

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A FORMULA FOR CONCENTRATED ELDER-FLOWER WATER.

Krembs recommends the following process for making a concentrated elder-flower water, from which he states the ordinary water can be extemporaneously prepared, of excellent quality, and of uniform strength:—­2 lbs. of the flowers are to be distilled with water until that which passes into the receiver has lost nearly all perfume.  This will generally happen when from 15 to 18 pounds have passed over.  To the distillate, 2 lbs. of alcohol are to be added, and the mixture distilled until about 5 lbs. are collected.  This liquor contains all the odor of the flowers.  To make the ordinary water, 2 ounces of the concentrated water are to be added to 10 ounces of distilled water.—­Buchner’s Report.

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PRACTICAL REMARKS ON SPIRIT OF WINE.

BY THOMAS ARNALL.

The strength of spirit of wine is, by law, regulated by proof spirit (sp. gr. .920) as a standard; and accordingly as it is either stronger or weaker than the above, it is called so much per cent. above or below proof.  The term per cent. is used in this instance in a rather peculiar sense.  Thus, spirit of wine at 56 per cent. overproof, signifies that 100 gallons of it are equal to 156 gallons of proof spirit; while a spirit at 20 per cent. underproof, signifies that 100 gallons are equal to 80 gallons at proof.  The rectified spirit of the Pharmacopoeia is 56 per cent. overproof, and may be reduced to proof by strictly adhering to the directions there given, viz., to mix five measures with three of water.  The result, however, will not be eight measures of proof spirit; in consequence of the contraction which ensues, there will be a deficiency of about [Symbol:  oz.]iv in each gallon.  This must be borne in mind in preparing tinctures.