m Bcientific Intelligence* [Oct. 



as we see dust, or other small bodies driven along by a common wind ; 

 there is also an obvious tremor produced in the copper pole, when the 

 instrument is in vigorous action, and we can perceive an evident vibra- 

 tion produced, as if by the impulse of an elastic fluid striking against 

 the opposite pole. 



** ] r, however, the opinion which you formerly suggested to me, and 

 which is countenanced by many facts, that the poles of the deflagrator 

 jure reversed, the copper being positive and the zinc negative, be cor- 

 rect, the phaenomena, as it regards the course of the current, will 

 accord, perfectly well, with the received electrical hypothesis." 



We must defer the succeeding articles until our next, for want of 

 room. 



y. Calculus of Cystic Oxide from a Dog; Constiiuents of that Sub^ 



stance, Sfc. 



The following are M. Lassaigne's description and analysis of a cal- 

 culus extracted from the bladder of a dog, which he found in the col- 

 lection of calculi belonging to M. Girard, Director of the Royal 

 Veterinary College of Alfort. 



It weighed about 38 grains troy; was of a yellowish colour, 

 semi-transparent, of an irregular form, glossy (lisse) on the surface, 

 and ronfusedly crystallized throughout its substance; specific gravity, 

 1*577. It consisted of 



Cystic oxide 97 5 



Phosphate and oxalate of lime 2*5 



The oxalic acid could not be obtained in an uncombined state, but 

 its existence was inferred from the property possessed by the residue 

 of the calculus insoluble in potassa, of being partially converted into 

 carbonate of lime by a slight calcination. 



M Lassaigne has examined the combinations of cystic oxide with 

 potassa, and ammonia, and with the muriatic, nitric, sulphuric, phos- 

 phoric, and oxalic acids. The muriate, which is crystallized in acicu- 

 lar radii, consists of 5*3 acid and 94<*7 oxide; the nitrate, cr3^stailized 

 in very slender needles, of 3*1 acid and 96"9 cystic oxide ; the sul- 

 phate, a viscid uncrystallizable deliquescent substance, of lO^ acid 

 an4 896 oxide, but M. Lassaigne suspects, that this compound haci 

 retained a portion of water ; the oxalate, in efflorescent acicular crys- 

 tals, contains 22 oxalic acid, and 78 cystic oxide. 



By means of ignition with peroxide of copper, M. Lassaigne has 

 ascertained that the composition of cystic oxide is as follows : 



Carbon 36 2 



Nitrogen 34;'0 



Oxygen 170 



Hydrogen 12'8 



100-0 

 (Ann. de Chim. et de Phys. torn, xxiii. p. 328.) 



VL Injlammalion ofGunpoxvderhy the Heat of slacJcing Lime. 



To determine whether the heat given out during the slacking of lime 

 wa« sufficient to fire gunpowder, a small quantity of it was put inlo a 

 glass tube closed at one end ; the tube was then placed in slack- 



