C »5S 3 



XXIX. Experiments on the Production of Cold by the Evapora- 

 tion of the Sulphuret of Carbon. By Alexander Marcet, M. D. 

 F. R. S. one of the Physicians to Guy's Hospital. 



Read July 8, 1813. 



1 HAD the honour, at an earlier period of this session, of giv- 

 ing to the Society, conjointly with Professor Berzelius, an 

 account of the alcohol of sulphur, or sulphuret of carbon, and 

 of noticing the remarkable volatility of that fluid. I have, since 

 that period, tried a variety of experiments on the subject, and 

 having found this compound more volatile than any other 

 known body, and capable of producing, by its evaporation, a 

 degree of cold of proportional intensity, I have been induced, 

 in order to render the history of the sulphuret of carbon more 

 complete, to present to the Society a brief account of my 

 experiments.* 



If the bulb of a small spirit thermometer be closely covered 

 with a bag of fine flannel, or still better, with a piece of fine 



* I would recommend to those, who may wish to repeat these experiments, to pre- 

 pare this substance by means of a large earthen tube of about one inch and a half in 

 diameter, instead of the small porcelain tubes, which are commonly used for this pur- 

 pose. The process is always a tedious one ; but a much more considerable quantity 

 of the sulphureous liquor is procured by the larger tube in an equal space of time. 

 The same tube can scarcely ever be used twice. About half a pint of the liquor may 

 be obtained in one process ; but the operation requires almost a whole day. Fresh 

 pieces of sulphur maybe successively introduced whilst the distillation is going on, and 

 without renovating the charcoal, as the occasional admission of air does not materially 

 affect the operation. The process would, no doubt, admit of further improvement. 



