210 ANNUAL OF SCIENTIFIC DISCOVERY. 



This invention claims the following advantages in practice : 1. The 

 gas so produced is cheaper than any other mode of artificial light, 

 costing, as is asserted by M. Gillard, only about one sixteenth the 

 average cost of coal gas. 2. The gas has no unpleasant odor, being 

 entirely free from the volatile hydrocarbons which are so peculiarly 

 offensive in oil and coal gas. 3. The products of its combustion are 

 almost solely water, so little carbonic acid resulting in the combustion 

 that practically it may be disregarded. 4. This mode of producing 

 gas may be applied to any existing gas-works by a slight modification 

 of the retorts, and without any essential change in other portions of 

 the apparatus the platinum cages being applied to the argand burn- 

 ers. 5. The cheapness of this mode enables us to apply it with great 

 advantage as a fuel for cooking and for numerous purposes in the arts. 

 For example, we saw, in the establishment of M. Christolef, the solder- 

 ing of silver plate accomplished, in a rapid and remarkably neat man- 

 ner, by a powerful jet of this gas, driven by a pneumatic apparatus. 

 Its perfect manageable ness, the ease with which an intense heat is 

 applied locally and immediately when it is wanted, coupled with ad- 

 vantages of employing for such a purpose so pOAverful a deoxidizing 

 agent as hydrogen, render this mode of soldering preferable to every 

 other, and peculiarly suited for the process of autogenous soldering. 

 6. The nuisances resulting from the presence of large coal gas-\vorks 

 in populous districts are entirely avoided by this mode, which is as 

 free from objection as a steam-engine. 7. The arrangements are so 

 simple and inexpensive that every establishment, where it is desired to 

 employ light and heat, may erect its own apparatus, even in the most 

 isolated situation, all the materials employed being everywhere acces- 

 sible. 



We merely add that the result of M. Gillard's invention in one par- 

 ticular differs from the anticipation of chemists ; that is, we should 

 expect from the decomposition of water in this mode the production 

 of carbonic oxide CO, carbonic acid CO 2 , and light carburetted hydro- 

 gen C 2 H, with a limited amount of free hydrogen. The result of his 

 experience, however, seems to establish the statements already made. 

 Communicated to Sillimcni's Journal, by Prof. B. Silliman, Jr. 



APPARATUS FOR THE EXPLOSION OF CARBURETTED HYDROGEN. 



A LITTLE apparatus, constructed by Mr. Billows, has been exhibited 

 at the London Polytechnic Institution, for the purpose of showing 

 some curious phenomena characteristic of carburetted hydrogen. A 

 file of 12 small glass tubes, about eight inches high and one quarter inch 

 diameter, are placed in a plate of perforated zinc, and covered by a glass 

 shade with an opening in the top ; these tubes form so many open gas- 

 burners, and, on turning the gas full on, burn steadily in the usual man- 

 ner ; but if the gas be lowered to such a point that sufficient hydrogen is 

 allowed to enter the tubes, and, mixing with its atmospheric air within, 

 form an explosive mixture, (which is about one of the former to eight of 

 the latter,) a continuous series of explosions occur, and the burning gas 

 is seen to descend in beautiful lambent green flames, sometimes tinged 

 with red. As the gases get more heated, the explosions are louder, 



