166 History of Mechanical Inventions and 



of its volume and was weakened 12°. The alcoholic vapour 

 was perceived by the smell. 



Into two bladders of equal size was put, into one eight 

 ounces of water, and into the other eight ounces of alcohol. 

 They were placed side by side, exposed to a slight heat. In 

 four days the water had entirely disappeared, while the alcohol 

 had scarcely lost an ounce of its weight. Mineral waters and 

 that of wells evaporate and deposit on the interior of the blad- 

 ders the saline matters which they contain. 



If the heat be conveniently managed, absolute alcohol may 

 be obtained in from six to twelve hours. Solar heat even is 

 sufficient to produce an anhydrous alcohol. 



Wine placed in prepared bladders contracts no bad odour ; 

 it assumes a deep colour, acquires more aroma, and a milder 

 taste, and becomes generally stronger. Spirits of turpentine 

 of 75° contained in a cylindrical glass closed with a bladder, 

 lost nothing in four years. Concentrated vinegar lost the half 

 of its volume in four months, the other half acquired more 

 consistency, and had no longer an acid taste. The liqueur of 

 orange flowers, was about one-third evaporated in a few months, 

 appeared to have a stronger odour, and consequently to have 

 lost nothing of its volatile principle. — Ferussac's Bulletin, 

 Mai 1828. 



3. On the employment of Iodine as a Dye. 



It appears fromanote by Pelletier that he ascertained, during 

 a recent journey in England, that a large quantity of periodu- 

 ret of mercury is sold in that country under the name of Eng- 

 lish vermilion, which is employed principally in the preparation 

 of paper hangings. Learning also that iodine was used in 

 printing calico, he analyzed a specimen of the colouring ma- 

 terial from Glasgow, and succeeded in forming a compound 

 which was a perfect imitation of the English salts. The pro- 

 portions which he found to succeed best were the following : 



Hydriodate of potash - . ^ 65 



.-r-r lodate of potash _ - - - 2 



loduret of mercury - - - 33 



loa 



