292 Proceedings of Philosophical Societies. [Al?TlM<y 



Potash 28-84 



Sulphuric acid 48*84 



Carbon 13-98 



Hydrogen 2-34 



Water 7-00 



101-00 



It thus appears, that in this salt four proportionals of carbon 

 united with four of hydrogen, are combined with one of sulphuric 

 acid, forming oil of wine. 



Mr. Hennel ascertained that this salt was identical with that 

 called sulphovinate of potash; and whilst preparing some of the 

 sulphovinates, for the purpose of comparing them with the salts 

 obtained from oil of wine in this manner, he found that a great 

 reduction of the saturating power of sulphuric acid was produced 

 by its mixture with alcohol; 440 grs. of acid mixed with an equal 

 weightof alcohol, requiring for theirsaturation only 398grs.ofpar- 

 tially dried carbonate of soda, whilst an equal weightof pure acid 

 required 535 grains of the same carbonate. This fact shows that 

 sulphuric acid, by mixture with alcohol, is immediately converted 

 into sulphovinicacid: and, in conjunction with the facts detailed 

 in the former part of the paper, it also evinces that the loss of 

 saturating power cannot be owing, as MM. Vogel and Gay- 

 Lussac have supposed, to the formation of hyposulphuric acid. 



By heating oil of wine either in solution of potash, or in water, 

 much of the excess of hydrocarbon which it contains is liberated 

 in the form of an oil, resembling in appearance some of the bal- 

 sams. This oil, as w ell as the crystals which form spontaneously 

 in oil of wine, yielded by analysis carbon and hydrogen, in pro- 

 portions nearly approximating to those of olefiant gas ; but in 

 the analyses, which were several times repeated, a slight loss 

 was always experienced, the cause of which Mr. Hennell was 

 unable to ascertain. 



- A paper on the Mathematical Principles of Suspension 

 Bridges, by Davies Gilbert, Esq. MP. VPRS. was also read; and 

 the reading of a paper by Mr. Herschel, on a new Method of as- 

 certaining the Parallax of the Fixed Stars, was commenced. 



March 16. — N. A. Vigors, Esq. and Pearson, Esq. 



were admitted Fellows, and the name of Hawkins, Esq. 



was ordered to be inserted in the printed lists of the Society. 

 The reading of Mr. Herschel's paper, of which we shall probably 

 give an account in our next, was resumed and concluded. 



A paper was also read. On the Expression of the Parts of 

 Machinery by Signs ; by C. Babbage, Esq. FRS. 



In contriving his calculating engine,* Mr. Babbage found 



• See Annals, N, S. vol, iv. 



