_A_, A bottle with two necks, the upper furnished with a ground-glass stopper. _B_, Loop of cord to hang the apparatus up by. _C_, Bladder, containing spirit, filled by means of the bottle _A_. _D_, Neck of bladder accurately secured to the under neck of the bottle _A_.] III. (Soëmmering.——VARNISH-MAKER’S ALCOHOL.) The bladder of an ox or calf, thoroughly cleansed from fat, and washed and dried, is nearly filled with rectified spirit, and then securely fastened and suspended in any dry situation, at a temperature of about 122° Fahr. In from six to twelve hours, when the heat is properly maintained, the spirit is generally sufficiently concentrated, and in a little time longer is rendered nearly free from water (anhydrous), or of the strength of 96 to 98%.——_Obs._ The same bladder will serve for more than one hundred operations. If not kept very nearly full, a portion of the spirit escapes through the empty part. To prevent this accident, a bottle with a double neck, of the shape represented in the _engr._, may be employed; by which means the bladder may be kept constantly full during the process. After the first or second time of using, the bladder gives alcohol sufficiently pure for all ordinary purposes. Before hanging the apparatus up, it is better to enclose it in a coarse potato-netting, to prevent any accident arising from the strain on the neck of the bladder. Soëmmering recommends both the inside and outside of the dry bladder to be smeared over 2 or 3 times with a strong solution of isinglass; but this is not necessary to the success of the process. IV. _Rectified Spirit._ (B. P. 1867.) _Spiritus Rectificatus._ Alcohol with 16 per cent. of water; obtained by the distilling of fermented saccharine fluids. Sp. gr. 0·838. V. _Proof Spirit._ (B. P. 1867.) _Spiritus Tenuior._ Take of rectified spirit, 5 pints; distilled water, 3 pints. Mix. Sp. gr. of product 0·920.