Prizes offered by the Hoyal Scottish Society of Arts. 389 



periments. In our repeated trials we have generally used 

 less than half a grain, and we have obtained unequivocal 

 proof of oxydation, by the evolved carbonic acid, when using 

 less than two-tenths of a grain. 



The apparatus employed is, in the main, identical with 

 that used in the analysis of graphite, but the Liebig tube is 

 in this case replaced by a vessel containing lime-water. 



Precautions are necessary to correct a slight error arising 

 from the evolution of a minute amount of carbonic acid from 

 the bichromate and sulphuric acid, caused by the presence 

 of a trace of organic matter, or of carbonate in the former. 



Operating on half a grain of diamond, we have in a first 

 process obtained half a grain of carbonate of lime, and using 

 the residuary matter have continued the oxydation, until at 

 length the amount of carbonic acid evolved, approached nearly 

 to that due to the entire weight of the diamond. In these 

 experiments, the carbonic acid, evolved by the bichromate 

 and sulphuric acid, is first expelled from the apparatus by a 

 particular mode of conducting the operation. — {The American 

 Journal of Science and Arts, Second Series, No. 16, July 

 1848, p. 110.) 



List of Prizes offered by the Royal Scottish Society of Arts, 

 for Session 1848-49. 



The Society proposes to award Prizes of different values (none to 

 exceed Thirty Sovorigns), in Gold or Silver Medals, Silver Plate, or 

 Money, for approved Communications, relative to Inventions, Dis- 

 coveries, and Improvements, in the Mechanical and Chemical Arts 

 in General, and also to means by which the Natural Productions of 

 the Country may be made more available ; and, in particular, to, — 



I. Inventions, Discoveries, or Improvements in the Useful Arts, 

 including the Mechanical and Chemical ; and in the Mechanical 

 Branch of the Fine Arts ; such as the following, viz. : — 



1. Mechanical Arts. 



1. Methods of Economising Fuel, Gas, &c., — of Preparing Su- 

 perior Fuel from Peat, — of Preventing Smoke and Noxious Va- 

 pours from Manufactories, — of Warming and Ventilating Public 

 Edifices, Private Dwellings, &c. — of constructing Economical and 



