CHEMISTRY. 187 



water, and the elements which remain namely, one of olefiant 

 gas and one of water constitute ether. 



From carbon and hydrogen mineral elements a great number of 

 organic substances can be produced. In fact, from acetylene the 

 following series of compounds have been obtained : 



Acetylene can be transformed (C 4 H 2 ) 



into 

 Ethylene " " (C 4 H 4 ) 



into 

 Aldehyde " " (C 4 H 4 O 2 ) 



into 

 Acetic acid " " (C 4 H 4 O 4 ) 



into 

 Glycolicacid " " (C 4 H 4 O 6 ) 



into 

 Oxygly colic acid " (C 4 II 4 O 8 ) 



into 

 Oxalic " " (C 4 H 2 O 8 ) 



Lecture by Dr. Grace Ccdvert. 



PRESERVATION OF SULPHURETTED HYDROGEN SOLUTION. 



At the last meeting of the Pharmaceutical Society of Paris, M. 

 Lepage, of Gisors, brought forward a process which he has 

 adopted for preserving solutions of sulphuretted hydrogen. All 

 chemists know that this useful reagent cannot be preserved long 

 in aqueous solution. The author has adopted for some years an 

 artifice which enables sulphuretted hydrogen solution to be kept for 

 12 or 15 months with scarcely any loss of strength. Instead of 

 using water, he saturates a mixtura of equal parts of pure glycerine 

 and water with sulphuretted hydrogen gas, and uses it in the ordi- 

 nary manner. None of the reactions are interfered with in the 

 least, whilst the solution possesses almost perfect stability. The 

 dilute glycerine dissolves less gas than distilled water will ; repre- 

 senting the solubility in the latter liquid by 100, that in the former 

 will be 60. 



Glycerine likewise prevents solution of sulphide of ammonium 

 from becoming colored, and M. Lepage believes that it has a 

 similar action on the sulphides of potassium and sodium. Chemi- 

 cal News. 



ORIGIN OF PETROLEUM. 



M. Berthelot regards petroleum as the result of purely mineral 

 reactions. Believing, with Daubree, that the alkaline metals exist 

 in a free state in the interior of the globe, he shows that by the 

 action of these on carbonic acid and earthy carbonates, at a high 

 temperature, acetylides of the alkalies are produced ; these com- 

 ing in contact with the vapor of water, acetylene would be set 

 free. But as h}*drogen and steam must also be present, and at a 

 very high temperature, the acetylene cannot subsist, and in its 

 place we find the products of its condensation, and also the prod- 



