ILLUMINATION". 



525 



vaporized, and water, acted on in form of 

 steam, by zinc, a permanent gas, consisting 

 mainly or wholly of bicarburetted hydrogen, 

 i. e., defiant gas, is produced. Olefiant gas 

 consists, by weight, of .86 of carbon and 

 .14 of hydrogen. The percentage of carbon 

 in petroleum, naphtha, &c., is always greater 

 than this, so that, while those oils simply va- 

 porized by heat seldom or never result in a per- 

 manent gas, it is further true that, owing to 

 the excess of carbon, the vapors, when burned, 

 are liable to smoke, and the flame lacks bril- 

 liancy. Dr. Elmer proposing to supply the de- 

 ficiency of hydrogen in the oil vapors by liber- 

 ating that gas from steam during oxidation of 

 iron filings, Dr. Levi Reuben, of New York, 

 suggested to him, as preferable, the plan of lib- 

 erating the hydrogen by oxidation of zinc, 

 which readily sublimes at the heat required for 

 the gas process, so as to mingle freely with the 

 steam, and secure rapid oxidation and a free 

 supply of the requisite hydrogen, but which 

 has especially the advantage of affording inci- 

 dentally, in the resulting white oxide of zinc, 

 a product having a sure commercial value, and 

 one which would, therefore, go far toward pay- 

 ing the cost of materials and labor. A simple 

 calculation showed the proportions of zinc, 

 water, and a given oil required, in order to set 

 free just the additional percentage of hydro- 

 gen necessary, if such chemical union be sup- 

 posed to take place, to convert the entire car- 

 bon of the oil into its 'equivalent of olefiant 

 gas; and, slight volatile impurities in the oil 

 excepted, the gas so produced must be almost 

 perfectly pure. The suggestions and data be- 

 ing adopted, the invention consists essentially 

 in their application and working out in practice. 

 It is presumed, though (it appears) not yet 

 proved by chemical tests, that the product in 

 this process consists nearly, or altogether, of 

 olefiant gas. Substantially, the method of pro- 

 ducing the gas is as follows: 1. Vapor of 

 water being admitted into a retort at white heat, 

 in which zinc has been brought to the state of 

 sublimation, oxidation of the metal occurs, the 

 white oxide of zinc produced ascending, and 

 being caught in suitably arranged boxes, so as 

 to be saved, the hydrogen of the water which 

 is meanwhile set free passing on into a second, 

 and less highly heated, retort; 2. Into this 

 second retort, the required relative proportion 

 of benzole, petroleum, or any suitable liquid 

 hydrocarbon, is at the same time continuously 

 admitted, its conversion into vapor at once 

 taking place; 3. The hydrogen gas and the oil 

 vapor being thus continually supplied in this 

 retort, and exposed in it to an extremely high 

 temperature, a corresponding volume of a per- 

 manent gas (probably olefiant gas) is contin- 

 uously and rapidly formed and delivered. The 

 gas resulting is, at least, incondensable, and 

 capable of being stored ; -vVhile the second retort 

 after the process needs not contain any residue 

 of carbon ; and further, if the zinc be volati- 

 lized in sufficient quantity, no. oxygen needs 



pass over into the second retort, and if it do 

 not, no worthless carbonic acid can enter into 

 the gas product obtained. In the apparatus, 

 the steam is supplied by a small boiler within 

 the furnace, and just beneath the first retort, 

 and in order to insure its entering the retort in 

 a state in which no condensation will occur, 

 the steam is superheated by passing on its way 

 through a coil of pipe exposed to the heat of 

 the furnace. In some trials of this method, 

 in which, in the earlier part of the process, a 

 deposit of carbon in powder d.id occur in the 

 second retort, it was found that, the heat being 

 sufficiently great, and a stream of hydrogen alone 

 being subsequently for a time admitted, all of this 

 solid deposit of carbon was cleanly taken up 

 and carried over in gaseous form into the gas- 

 ometer. This fact appears incidentally to con- 

 firm the theory of the formation of the gas, and 

 of its character already given ; and the obtain- 

 ing of an illuminating gas in this way from 

 hydrogen and finely divided solid carbon 

 (soot) has been included in the patent. An 

 important advantage of the method of gas mak- 

 ing now described is in the circumstance that 

 since (if properly conducted) no oxygen can 

 gain access within the generating retort, not 

 merely is there no worthless product of com- 

 bustion already in the gas as made, but there 

 can, of course, occur no waste whatever by 

 burning up in the retort of a portion of the 

 gas, as too generally occurs in the making of 

 coal gas: the gas formed is protected from 

 chemical agencies, and the whole of it must 

 be delivered and secured. The gas as produced 

 in the trials thus far made by Dr. Elmer, gives 

 a white, solid, intense, and beautiful light; 

 but exact tests of consumption of material, il- 

 luminating power, &c., appear not yet to have 

 been made. 



Air Light for Locomotives. Dr. George Hand 

 Smith, of Rochester, N". Y., has invented ar. 

 apparatus for burning any permanent gas, as 

 ordinary coal gas, in such way as to secure an 

 intense heat, and the ignition to whiteness of 

 a small cylinder of lime, through means of sup- 

 plying to the burning gas an abundance of oxy- 

 gen, by mechanically forcing out in connection 

 with the issue of gas from each burner a jet of 

 atmospheric air, and which, previously to its 

 escaping, has been also highly heated. In a 

 word, his invention consists in applying the 

 principle of the common forms of air or atmos- 

 pheric light, in lieu of the more expensive 

 oxygen and hydrogen gases, and with the ad- 

 dition of heating the supplied air, to the pro- 

 duction of a lime light. His arrangement ap- 

 pears thus far to have been expressly designed 

 for use on railroads. The cylinder of lime 

 being fixed at the focus of the parabolic reflect- 

 or employed for projecting the light, as now, 

 in front of the locomotive, the lime is rendered 

 incandescent by burning in a circle surround- 

 ing it and directed upon it four jets of the 

 compound gas described, and issuing from as 

 many separate burners. Two gas holders 



