64 Gleanings from the International Exhibition. 



GLEANINGS FROM THE INTERNATIONAL EXHIBITION. 



Production of Alcohol and other Organic Substances by Synthesis. 

 — In an obscure corner of a case in the French department may be 

 found a bottle of alcohol, differing in no respect from that obtained 

 by the usual process of fermentation, except in its mode of origin, it 

 having been formed synthetically. The credit of the exceedingly 

 interesting discovery of the possibility of forming this and analagous 

 compounds, that have so long been regarded as belonging exclusively 

 to organic chemistry, is due to M. Berthelot, who ascertained that 

 when olefiant gas (C 4 H 4 ) is agitated for a long time with many 

 thousand concussions with sulphuric acid (S0 3 ,HO), that sulph- 

 ethylic acid is produced as indicated by the following formula : — 

 C 4 H 4 + 2(HO,SO,) = C JH 5 0,S0 3 ,HO,S0 3 . When sulphethylic acid is 

 heated with water, alcohol distils over, and sulphuric acid remains 

 behind. In connection with the artificial productions of alcohol, M. 

 Berthelot' s researches on the formation of acetjdene are very im- 

 portant, as tending still further to break down the distinction be- 

 tween organic and inorganic chemistry. Acetylene is one of the 

 most permanent of the hydrocarbons ; its composition is expressed 

 by the formula C 4 H 2 . It is produced by the action of the induced 

 electric spark, or by the aid of heat from olefiant gas, and is also 

 developed by the action of heat on the hydrocarbons benzole and 

 naphthaline. Berthelot has succeeded in preparing acetylene by the 

 direct union of its elements, carbon and hydrogen. The carbon is 

 first purified by the action of chlorine at a high temperature. This 

 removes sulphur and metallic impurities in the form of volatile chlo- 

 rides. The carbon thus obtained in a perfectly pure state may be 

 submitted to the action of hydrogen, aided by the highest tempera- 

 ture that it is possible to obtain, but no union will take. place. In 

 the like manner the inductive spark is equally powerless to effect 

 their union. If, however, an electric arc is caused to pass between 

 two charcoal poles or electrodes surrounded by an atmosphere of 

 hydrogen, union takes place as soon as the spark commences to pass. 

 Acetylene being produced, and its production continued as long as 

 the electric arc is maintained, the acetylene produced around the 

 poles may be carried away by a current of hydrogen, and condensed 

 by passing through an ammoniacal solution of protochloride of 

 copper. In this manner it is easy to obtain large quantities of ace- 

 tylene, which is readily liberated in a free state by the action of 

 hydrochloric acid. Acetylene is very important, as it presents a 

 basis from which other bodies may be obtained ; thus Berthelot has 

 demonstrated that by the simple addition of hydrogen it can be 

 changed into olefiant gas, and that from olefiant gas alcohol can be 

 formed, from alcohol ether, and thus the commencement be made of 

 a chain of compounds, all of which have been hitherto regarded as 

 belonging exclusively to the domain of organic chemistry. 



Ancient Egyptian Jewellery. — In the gallery of the Turkish 

 court there is a case of ancient Egyptian jewellery, taken from an 



