400 Miscellaneous Intelligence. 



evaporation, will yield well crystallized meconiate of morphia of 

 a pale straw-colour. — Gior. di Fisica, viii. 218. 



15. Rectification of Alcohol at common Tcmperatvres. — M. Paget 

 Descharme proposes to rectify alcohol in the large way by ex- 

 posing to its vapour deliquescent salts ; thus he puts into a vessel 

 with a flat bottom a given quantity of weak alcohol ; he then puts 

 a portion of pulverized muriate of lime into a dish, and places it 

 upon feet, or otherwise, over the alcohol in the first ; this is 

 closed hermetically, or a cover fastened on by pasted slips of 

 paper, and the whole left for four or five days, in which time the 

 alcohol strengthens, and the muriate deliquesces ; the muriate is 

 then removed, and a fresh portion introduced, and this is repeated 

 until the alcohol is sufficiently concentrated. Th'is is an operation 

 common enough in our laboratories : it remains to be seen whether 

 it can be economically adopted in the large way t — Ann. de Chim. 

 xxix. 328. 



16. Hygrometric Property of Sulphuric Acid. — The quantity of 

 water that sulphuricacidsp.gr. 1.840 is capable of absorbing 

 from an atmosphere saturated with vapour, has lately been deter- 

 mined, by exposure of 50 grains of acid of the above strength to 

 such an atmosphere. In the course of four months, it gained 

 423.2 grains of water, considerably more than eight times its ori- 

 ginal weight, its sp. gr. being diminished to 1.0706. — T. G. 



17. Simple method of exhibiting the Deflection of the Magnetic 

 Needle by the Electric Current. — A striking method of exhibiting 

 the deviation of the magnetic needle, whilst under the influence 

 of the voltaic conducting wire, consists in employing one of M. 

 de la Rives' floating spirals, in the centre of which, and parallel 

 with it, is placed a suspended magnetized needle. The moment the 

 plates of an apparatus, so constructed, are dipped into an acid, 

 the needle places itself at right angles to the spiral wire : thus 

 shewing one of the principal facts of electro-magnetism, although 

 upon a small scale, yet in a very decided manner T. G. 



18. Necessity of Water in the preparation of Lead-plaster. — At- 

 tempting to form lead-plaster, the Emplastrum Plumbi of the Phar- 

 macopoeice, without the use of water, steam being the source of heat, 

 I was surprised to find after several hours, during which time the 

 litharge and oil had been kept at a temperature of 220°, or there- 

 about, and constantly stirred, not the slightest appearance of 

 combination ; upon the addition of a small quantity of boiling 

 water, the oil and oxide immediately saponified; water appeared, 

 therefore, to be essential to the formation of the plaster. It also 

 appeared probable the oxide might be in the state of hydrate ; to 



