CHEMICAL SCIENCE. 269 



Chemists know that by following an accustomed routine, alcohol (an organic 

 substance) may be decomposed into two simpler compounds, viz., water, and 

 bicarbureted hydrogen. The plan is as follows : alcohol is placed in a retort, 

 with a portion of concentrated sulphuric acid. On the application of heat, 

 carbureted hydrogen gas is liberated, which burns with great brilliancy, while 

 steam and a measure of water is left behind. The inverse operation to this 

 would consist in uniting the bicarbureted hydrogen and water in such pro- 

 portions as to form alcohol This, and other like operations, chemists have 

 deemed impossible. It was the problem which M. Berthelot, of France, pro- 

 posed to himself, and which has resulted in a complete solution. The point 

 which is, perhaps, the most remarkable of the process, is that the solution is 

 grounded on the use of the same body which hitherto has served to effect 

 the decomposition of alcohol. The same sulphuric acid which at 160 degrees 

 Centigrade acts to separate water from the carbureted hydrogen acts alto- 

 gether differently at the ordinary temperature ; hi contact with the gaseous 

 body it gradually absorbs and disposes it to re-enter into combination. 



This is the plan followed by M. Berthelot in his experiments : Having pre- 

 pared about thirty quarts of bicarbureted hydrogen, he placed them hi a 

 close retort with 900 grammes of pure and highly concentrated sulphuric acid. 

 To this was added five or six volumes of water. The whole was then sub- 

 mitted to successive distillations, carbonate of potash being used to retain the 

 water. In the last condenser, M. Berthelot found 52 grammes of an alcoholic 

 liquid, corresponding to 45 grammes of absolute alcohol, and three fourths of 

 the gas employed ; the remainder was lost hi the manipulations. This alcohol 

 possessed all the properties of ordinary alcohol ; the same taste and odor, the 

 same point of ebulhtion, the same inflammability at the approach of a body 

 in combustion, and the same colored flame ; it had, too, the same dissolving 

 power and the same reaction on all bodies it was indeed regenerated alco- 

 hol. The bicarbureted hydrogen used by M. Berthelot was obtained from 

 the decomposition of alcohol; he made also other experiments with bicarbu- 

 reted hydrogen found hi common illuminating gas, and obtained the same result. 

 In this case, then, beyond a doubt chemistry has succeeded hi making and un- 

 making the same composition of organic origin, and (perhaps the curious 

 point) it was made in both instances by the same reagent, by a mere change 

 of temperature. M. Berthelot had already obtained analogous results by ope- 

 rating on the products resulting from the decomposition of oleaginous sub- 

 stances. By placing these products together and letting them act slowly at a 

 suitable temperature, he succeeded not only hi regenerating the natural fats, 

 but associating these products of decomposition hi different manners, he suc- 

 ceeded hi forming bodies analogous to the fats which are naturally formed. 

 What can be concluded from these different examples, but that after being 

 successful in transforming a composite substance into two others, the chemist 

 has always a right to hope he may be able to reunite them and remake that 

 which gave them birth. In any event success would be an interesting fact 

 for science, and besides such a fact would give rise to important applications. 

 Thus when dilute sulphuric acid is allowed to act upon cane sugar, the latter 

 is converted into glucose, or the sugar of grapes the grape sugar taking an 



