Intelligence and Miscellaneous Articles. 143 



manent in the air, but still yields the odour of rancid butter. Ex- 

 posed to a cun-ent of dry air at 212°, this salt loses 3-25 per cent, of 

 water ; at 392° it fuses, and again loses 2*80 per cent. Thus dried, 

 the salt consists of [C^ (H^ Ba) O'^] . By dry distillation it yields a non- 

 acid oily body ; the last mother-^¥aters yield acetate of barytes. 

 Butyro-acetic acid readily yields an rether with alcohol and sulphuric 

 acid. It has the smell of fruit. With respect to this acid, it will 

 be obser\-ed that it is isomeric with metacetonic acid, obtained during 

 the last year by M. Gottlieb from potash and sugar. M. Nickles 

 has not had sufficient opportunity to ascertain the identity of these 

 two acids. — Journ. de Chim. Med., Novembre 1846. 



ON THE IGNITION OF BRASS WIRE IN THE VAPOUR OF ALCOHOL. 

 BY M. REINSCH. 



It has hitherto been supposed that the property of igniting in the 

 wick of a spirit-lamp was peculiar to a coil of platina or palladium wire. 

 The author has lately discovered that all other metals possess this pro- 

 perty, which do not melt at a red heat, even whether they oxidize or 

 not. If a coil of piano-wire be placed in the wick of a spirit-lamp 

 (absolute alcohol), and it be allowed to burn till the spiral is suffi- 

 ciently red-hot and then extinguished, the spiral remains red-hot for 

 a few seconds and then ceases to be so. If the lamp be thus lighted for 

 three or four times, the iron wire remains red-hot exactly like a pla- 

 tina wire, and the peculiar odour of aldehyd and acetic acid is at the 

 same time developed. If the experiment does not succeed, the flame 

 of the alcohol must be covered with a glass tube, and not extin- 

 guished till this precaution has been taken. M. Reinsch states that 

 he could not succeed at first with brass, silver and copper wire ; 

 brass wire should be thin, and the spirals made as close to each other 

 as possible, but they must not touch ; the flame of the alcohol also 

 should not be continued longer than is necessary to ignite the brass 

 wire, and after this it ought to be suddenly extinguished to prevent 

 the wire from melting, and to prevent the spirals from toucliing each 

 other. Copper and brass wire continue as vividly red-hot as platina 

 wire, though they are gradually acted upon by the acetic acid and 

 afterwards volatilized. The silver wire does not remain so long ig- 

 nited. The wires of the metals mentioned absorbing heat too rapidly, 

 remain but incomj)letely red-hot, but a thicker iron wire remains red, 

 being not so good a conductor of heat. Silver wire becomes but im- 

 perfectly ignited, because being ignited, it becomes so soft that the 

 spirals soon touch each otlier. The same occurs with a gold wire. 



Tlie author iilso succeeded in producing ignition with charcoal ; 

 for this ))uri)ose a fragment of charcoal is placed in the wick ; the 

 alcohol is removed from the lam]), except sufficient to moisten the 

 wick, which is to be lighted and the flame is to be cautiously extin- 

 guished ; these exi)eriinents, the author observes, explain a fact 

 which has hitherto been an enigma — the ignition of platina and 

 the inflammation of hydrogen gas by s))ongy ])latina. Thus in the 

 first experiment, the vapour of alcohol being imperfectly consumed 



