186 ANNUAL OF SCIENTIFIC DISCOVERT. 



quainted with a great number of carburetted hydrogens, either ob- 

 tained naturally from the organic kingdom, such, for example, 

 as otto of roses, the essences of lemon, bergamot, cloves, neroli, 

 and the solid substances called caoutchouc, gutta-percha, as well 

 as a great number of others obtained through the destructive dis- 

 tillation of organic matters, as well as coals, such as ethylene, 

 amylene, propylene, etc. M. Berihelot obtained acetylene by pass- 

 ing through a glass globe a slow current of hydrogen gas, in which 

 globe there were the two carbon points of an electrical battery in 

 a state of incandescence, producing what is usually called the 

 electrical light. Under this intense heat and electrical current the 

 hydrogen introduced by him combined with the carbon of the 

 points, and produced acetylene, which he collected by passing it 

 through an ammoniacal solution of protochloride of copper, get- 

 ting a coppery precipitate, or acetylide of copper, from which he 

 easily isolated acetylene, thus proving to the chemical world the 

 possibility of the artificial production of a carburetted hydrogen. 



This discovery, which astonished the scientific world, was soon 

 followed up by a series of facts most interesting to relate. M. 

 Berthelot placed in a small flask, to which was attached a tube to 

 give exit to any gas which might escape, some acetylide of cop- 

 per, together with zinc and ammonia, and on heat being applied 

 a chemical reaction ensued by which two atoms of hydrogen were 

 added to acetylene, converting it into ethylene or heavy carburet- 

 ted hydrogen, also called olefiant gas. 



This, though existing in large quantities in common coal gas, 

 cannot be isolated, owing to the numerous compounds with which 

 it is mixed. Therefore it is necessary to adopt some chemical re- 

 action to produce it in a pure state. To attain this end, 1 part of 

 alcohol is mixed with 3 parts of vitriol or sulphuric acid, and on 

 heat being applied each chemical equivalent of alcohol loses 2 

 equivalents of water; the remaining element of that alcohol, 

 being olefiant gas, is liberated, and can be examined. What 

 gives interest to this chemical reaction is, that whilst }'ou thus un- 

 fold, under the influence of heat, alcohol into olefiant gas and 

 water, you can, if we follow M. Berthelotfs process, namely, 

 of placing at the bottom of a large glass globe a small quantity 

 of concentrated sulphuric acid, and then fill the capacity of the 

 large glass globe with olefiant gas, and keep the same in a con- 

 stant state of agitation, 3*011 will, after having imparted to the 

 vessel some 40,000 or 50,000 rotatory motions, find that the olefi- 

 ant gas has been absorbed by the vitriol ; that it will have fixed 

 two equivalents of water, and that it will have thus converted the 

 olefiant gas- into alcohol, which can be isolated by subsequent 

 chemical manipulations. Therefore from carbon and hydrogen 

 you Avill notice that we first produced acetylene, and this sub- 

 stance we have converted into olefiant gas, and which in its turn 

 has been transformed into alcohol, which alcohol you can easily 

 convert into ordinary ether, or into acetic ether, spirit of nitre, or 

 nitric ether, etc. ; or you can also by oxidizing convert it into a 

 substance called aldehyde. To convert alcohol into ether, all you 



i "i 



have to do is to remove from alcohol one chemical proportion of 



