1867.] CJiemistry. 243 



acid is produced, in very small quantity it is true, but sufficient for 

 the author to identify and determine. Mr. Chapman took especial 

 pains to purify the lamp-black used in the experiment, so as to 

 preclude the possibility of any hydrogen compound being present. 



After this Mr. Parkinson gave an account of " Some Alloys of 

 Magnesium, and its behaviour with non-metallic elements." The 

 details given by the author were very long, and for a full account 

 we must refer the reader to the ' Journal of the Chemical Society ' 

 for March, 1867. It is sufficient to say that none of the alloys 

 of magnesium promise to be of any utility. Some of them, how- 

 ever, are possessed of curious properties. Bismuth, for example, 

 with 10 per cent, of magnesium, forms an alloy which deliquesces 

 when exposed to the air. The action of air and moisture is so 

 great that it hisses distinctly when held in the hand. Antimony, 

 with 10 per cent, of magnesium, behaves similarly. All the alloys 

 are very brittle, and are easily tarnished. The one which seems 

 the most permanent is that with zinc. The two metals must be 

 fused together in an atmosphere of hydrogen, for when heated 

 together in the air or under a flux the reaction is violent and 

 explosive. The most interesting of the compounds formed with 

 non-metallic elements is that with silicium. When silica is heated 

 to redness with magnesium filings, silicide of magnesium is pro- 

 duced, which decomposes water and causes the evolution of 

 spontaneously inflammable silicide of hydrogen. 



On the same evening Mr. E. H. Smith read a paper " On the 

 Oxidation of Ethylic Benzoate." 



At the meeting on December 20, Mr. W. H. Perkin read an 

 important paper " On the Bibasicity of Tartaric Acid." Tartaric 

 acid has, until lately, been regarded as bibasic; but its tetratomicity 

 being established, some chemists have found reasons for considering 

 it tetrabasic. These conclusions have been drawn from the com- 

 position of some metallic combinations ; but Mr. Perkin has studied 

 the replaceable hydrogen in a different manner, and from the 

 examination of new derivatives of the acid, establishes its bibasicity. 

 We must refer the reader interested in this question to the original 

 paper, which will be found in the 'Journal of the Chemical Society,' 

 for March, 1867. 



At the same meeting, a paper by Dr. Hunter, " On the Absorp- 

 tion of Vapours by Charcoal," was read. As in the author's 

 previous experiments, cocoa-nut charcoal was employed. The 

 vapours experimented upon were such as those of aniline, carbolic 

 acid, aldehyde, &c, and the determinations have no immediate 

 practical value. 



Mr. Herbert M'Cleod afterwards exhibited a new continuous 

 aspirator of his contrivance. This form of apparatus could not 

 be made intelligible without an engraving. Its only advantage 



e 2 



