468 New Electrical Battery. — Morphia, — Amhcr. 



performed the experiment, and which she certainly did, to the 

 satisfaction of himself and fuiiily, and of other friends who wit- 

 nessed it. 



See the whole of Lady M.'s correspondence on the subject, in 

 the fonrth volume of Dr. H.'s Philosophical Recreations above 

 referred to. ■ 



NKW ELECTRICAL BATTERY. 



Dr. Dana, of Harvard University in America, has constructed 

 an electiical battery of plates, extremely portable and compact, 

 and from his experinjents appearing to be very powerful. It 

 consists of alternate plates of flat glass and tin foil, the glass 

 plates beii)G: on all sides two inches larger than those of foil. The 

 alternate plates of tin foil are connected together, i. e. the 1st, 

 3d, .5!!i, 7fh, &c. on one side, and the other series, or 2d, 4th, 

 6th, 8!h, &;c. on the other side, slips of tin foil extending from 

 the sht-et to the edge of the glass plates for that purpose. These 

 connexions unite together all the surfaces, which, when the bat- 

 tery is charged, take by induction the same state. A battery 

 constructed in this way contains, in the bulk of a 4to volume, a 

 very powerful instrument ; and when made of plate glass, it is 

 extremely easy, by varnishing the edges, to keep the whole of 

 the inner smfaces from the air, and to retain it iq a constant 

 state of dry insulation. — • 



MORPHIA. 



Dr. Thomson has given the following as the easiest method 

 for obtaining pure morphia: Into a strong infusion of opium 

 pour caustic ammonia. Separate the precipitate by the filter. 

 Evaporate the solution to about a sixth, mix it with more am- 

 monia, and a deposit of impure morphia is obtained. Collect the 

 deposit by filter, and wash it with cold water. When well drained, 

 pour a litle alcohiil nw it, and let the alcoholic liquor pass through 

 the filter: it will carrv off a good deal of colouring matter, and 

 very little of the morphia. Dissolve the impure morphia in acetic 

 acid, and mix the deep-brown solution with ivory black. Agitate 

 the li(|ii(»r frequently for 24 hours, filter it, and the liquid will 

 pas^ thi'>n!;h colourless. If ammonia be now dropped into it, pure 

 morphia falls in the state of a white powder. If this precipitate 

 be dissiiked in alcohol and slowlv evaporated, the morphia is ob- 

 tained in crystals (they are rectangular prisms) perfectly white, 

 of a pearly lustre, destitute of smell, and of an intensely bitter 

 taste. Pure morphia, pa'^sed slowly through red hot peroxide 

 of copper, is converted entirely into carbonic acid and water,—. 

 Annules, No. 90, — ^ - 



AMBEH. 



Dr.. Brewjter maintains, from a number of experiments and 

 th"!i rt'oilts. that amber is an indurated vegetable juice. 



BURNiNa 



