£36 0\ THE QUANTITY Ot? CARfeOtt IN CARBONIC ACID. 



100 grs. carbo- Hence we conclude, that 100 grains of carbonic acid con* 

 fainTs^of" tam 28'GO °f carbon, which docs not greatly differ from the 

 carbon. results of the experiments of SmithsOn Tennant, Esq. oa 



the nature of diamond. See Phil. Trans. 1797. 

 Mr. Tennant's This gentleman made his experiment in the following 

 experiment! nianuer. A quarter of an ounce of nitrate of potash was 

 rendered somewhat alkaline by exposure to heat, in order 

 that it might more readily absorb carbonic acid ; it was then 

 put into a gold tube with 2§- grains of diamond, and being 

 subjected to heat, the diamond was converted iuto carbonic 

 acid, by uniting with the oxigen contained in the nitric acid. 

 The carbonic acid thus produced combined with the potash, 

 and on pouring a solution of muriate of lime into a solution 

 of this salt, he obtained a precipitate of carbonate of lime, 

 this, being decomposed by muriatic acid, gave as much car- 

 bonic acid gas as occupied the space of 10*1 ounces of wa- 

 ter. The thermometer was at 55° Fahrenheit, the barome- 

 ter 2j)'80. In a second experiment he procured a larger 

 quantity, or equal to 10*3 ounces of water. 

 ga?e27or27-8. If we therefore consider an ounce of water as consisting 

 of 480 grains, and a cubic inch of water equal to 2o3 grains, 

 and then make the proper corrections for temperature and 

 pressure, one of his experiments will give about 27 per cent, 

 the other about 27*80 for the carbon in carbonic acid, which 

 is somewhat less than our estimate; but the difference may 

 easily be accounted for, from the different methods employed. 

 Guytoirsex- The experiments of Guyton, as detailed in the Annates de 



fo iiTe"en n d ed Chimie > vol « X*XI, P*ge 7&, are liable to very strong objec- 

 ou. tions ; but at the same time the candid manner, in which he 



has related every circumstance, merits considerable praise. 

 ft is impossible, however, not to observe, that the quantity of 

 gas before and after the experiment could not, from the 

 construction of his apparatus, be very rigorously ascertained. 

 We object also to nitrous gas as a test for oxigen ; and as it 

 is acknowledged, that the wooden support included in the 

 oxigen gas took fire, the product of carbonic acid must have 

 been influenced by it ; so that, if no chance of errour had 

 existed in estimating the carbonic acid gas from the residuum 

 after barytic water had absorbed a part, still the result would 

 Lot have been satisfactory. 



The 



