of the fixed Alkalis. 10$ 



In an experiment on the decomposition of water by the 

 basis of soda, the mercury in the barometer standing at 

 30*4 inches, and in the thermometer at 52° Fahrenheit, the 

 volume of hydrogen gas evolved by the action of '054 grains 

 of basis equalled that of 326 grains of quicksilver. Now 

 this at the mean temperature and pressure would require for 

 its conversion into water, '0172 of oxygen, and '054 + 

 •0172 = -0712 : '054 : : 100 : 76 nearly ; and according to 

 these indications, 100 parts of soda consist of nearly 76 

 basis, and 24 oxygen. 



In another experiment made with very great care, '052 of 

 the basis of soda were used ; the mercury in the barometer 

 was at 29*9 inches, and that in the thermometer at 58° Fah- 

 renheit. The volume .of hydrogen evolved was equal to that 

 of 302 grains of mercury ; which would demand for its sa- 

 turation by combustion, at the mean temperature and pres- 

 sure, *01549 grains of oxygen ; and 100 parts of soda, ac- 

 cording to this proportion, would consist nearly*of 77 basis, 

 and 23 oxygen. 



The experiments which have been just detailed, are those 

 in which the largest quantities of materials were employed ; 

 I have compared their results, however, with the results of 

 several others, in which the decomposition of water was 

 performed with great care, but in which the proportion of 

 the bases was still more minute: the largest quantity of ox- 

 ygen indicated by these experiments was, for potash 17, and 

 for soda 26 parts in 100, and the smallest 13, and 19; and 

 comparing all the estimations, it will probably be a good 

 approximation to the truth, to consider potash as composed 

 of about six parts basis and one of oxygen ; and soda, as 

 consisting of seven basis and two oxvgen. 



VII. Some general Observations on the Relations of the Bases 

 of Potash and Soda to other Bodies. 

 Should the bases of potash and soda be called metals? 

 The greater number of philosophical persons to whom this 

 question has been put, have answered in the affirmative. 

 Tfaey agree with metals in opacity, lustre, malleability, con- 

 ducting' 



