278 



SCIENCE-GOSSIP. 



ACETYLENE : A NEW ILLUMINANT. 



T)ROFESSOR Vivian B. Lewis gave an im- 

 portant address before the Society of Arts, in 

 London, on January 16th, on a remarkable dis- 

 covery which will affect the illumination and 

 heating of our houses and public buildings without 

 the aid of coal. The meeting was largely attended 

 by managers and others connected with gas-supply, 

 the chair being occupied by Dr. William Anderson, 

 F.R.S. 



Professor Vivian Lewis called his paper " The 

 Commercial Synthesis of Illuminating Hydro- 

 carbons." He reminded the meeting that the two 

 methods most used in chemical science for 

 determining the composition of bodies, are 

 "Analysis " or the breaking up of compounds into 

 their ultimate constituents, and " Synthesis," which 

 is the building up of the compound from the 

 elementary matter which forms it. He then pro- 

 ceeded, after further introduction, to describe the 

 production of Acetylene, the following paragraphs 

 occurring in his paper : 



" In all the phenomena of ordinary combustion 

 which we employ to provide us with heat and light, 

 there are no compounds of greater interest than the 

 class of organic bodies which, being formed of 

 carbon and hydrogen in various proportions, have 

 been termed hydro-carbons, and it is to this class 

 of bodies that all the gases which can be used as 

 ordinary illuminants owe their luminosity. Amongst 

 the hydro-carbons, the simplest compound is acety- 

 lene, in which two atoms of carbon are united with 

 two atoms of hydrogen ; and it has long been 

 known that, if a stream of hydrogen is passed 

 through a globe in which the voltaic arc is pro- 

 duced between carbon points from a sufficiently 

 powerful current, this gas is produced in minute 

 quantities. The direct combination of carbon and 

 hydrogen in the electric arc is a true case of syn- 

 thesis, and if we could form acetylene in this way 

 in sufficiently large quantities, it would be perfectly 

 easy to build up from the acetylene the whole of 

 the other hydro-carbons which can be used for 

 illuminating purposes. For instance, if acetylene 

 be passed through a tube heated to just visible red- 

 ness, it is rapidly and readily converted into benzol ; 

 at a higher temperature naphthalene is produced, 

 whilst by the action of nascent hydrogen on acety- 

 lene, ethylene and ethane can be built up. From 

 the benzol we readily derive aniline, and the whole 

 of that magnificent series of colouring matters 

 which have gladdened the heart of the fair portion 

 of the community during the past five-and-twenty 

 years, whilst the ethylene produced from acetylene 

 can be readily converted into ethyl alcohol, by con- 



secutively treating it with sulphuric acid and water, 

 and from the alcohol, again, an enormous number 

 of other organic substances can be produced. Thus 

 acetylene can, without exaggeration.be looked upon 

 as one of the great keystones of the organic edifice, 

 and, given a cheap and easy method of preparing 

 it, it is hardly possible to foresee the results which 

 will be ultimately produced. 



" From acetylene we can produce all those bodies 

 which we are accustomed to look upon as the most 

 important ones in our coal-gas, and which, up to 

 the present time, have never been produced from 

 anything but coal, hydrocarbon oils, or other 

 organic matter undergoing destructive distillation, 

 but it has often occurred to those of us who are 

 interested in the manufacture of illuminating gas, 

 that as the supply of coal gets smaller, and as oil 

 in time begins to share the same fate, some new 

 sources for our illuminants and our fuels must 

 be sought ; and in my mind, at any rate, the 

 synthetic production of hydrocarbons has long 

 been a day dream, which I, however, never 

 expected to see possible on a commercial scale. 



" As is so usual in the history of discovery, the 

 factor which has endowed us with the power of 

 doing this was not the outcome of an elaborate 

 research, but was found by chance during the 

 search for something else. Whilst working with 

 an electric furnace, and endeavouring by its aid 

 to form an alloy of calcium from some of its 

 compounds, Mr. T. L. Willson noticed that a 

 mixture containing lime and powdered anthracite, 

 under the influence of the temperature of the arc, 

 fused down to a heavy semi-metallic mass, which 

 having been examined, and found not to be the 

 substance sought, was thrown into a bucket 

 containing water, with the result that violent 

 effervescence of the water marked the rapid 

 evolution of a gas, the everwhelming odour of 

 which enforced attention to its presence, and 

 which, on the application of a light, burnt with 

 a smoky, but luminous flame. 



" Investigation into the cause of this phenomenon 

 soon showed that in a properly constructed electric 

 furnace, finely ground-up chalk or lime, mixed with 

 powdered carbon in any form, whether it were char- 

 coal, anthracite, coke, coal, or graphite, can be fused 

 with the formation of the compound known as 

 calcic carbide, containing forty parts by weight of 

 the element calcium, the basis of lime, and twenty- 

 four parts by weight of carbon, and that, on the 

 addition to this of water, a double decomposition 

 takes place, the oxygen of the water combining 

 with the calcium of the calcic carbide to form 



