with soda. 



"3112 NATURE AND DECOMPOSITION OF THE FIX^D AtKALTS, 



eqxial in volume to 191 grain measures of mercury, and the 

 proper corrections being made as in the former case, this 

 gas would weigh '01189 of a grain. 

 Mean 86 1 base But 'O? + -01189 — '08189 : 07 : : IGO : 85'48 nearly, 

 oxige . j^^ ^^^^^ ^^ potash will consist of 85*5 of basis and 14'5 of 

 oxigen nearly. And the mean of the two experiments will 

 be 86-1 of basis to 13*9 of oxigen for 100 parts. 

 Experiment In the most accurate experiment that I made on the com- 



bustion of the basis of soda '08 parts of the basis absorbed 

 a quantity of oxigen equal to 208 grain measures of mer- 

 cury ; the thermometer being at 56° Fahrenheit, and the 

 barometer at 29*4; and this quantity, the corrections being 

 made as before for the mean temperature and pressure, 

 equals about '02 grains of oxigen. 

 80 base to 20 And as '08 + '02 = 'lO : '08, : : 100 : 80, ICO parts of 

 oxigen. soda, according to this estimation, will consist of 80 basis to 



20 of oxigen. 



Increa<!e of In all cases of slow combustion, in which the alkalis 



ed more'o'xf- ^^^^ "^t carried out of the tray, I found a considerable in- 



gen crease of weight; but as it was impossible to weigh them 



except in the atmospherCr, the moisture attracted rendered 



but less to be the results doubtful ; and the pro[)ortioa,s from the weight 



epen ec on. ^^ ^j^^ oxigen absorbed are more to be depended on. In 



the experiments in which the processes of weighing were 



most speedily performed, and in which no alkali adhered 



- to the tube, the basis of potash gained nearly 2 parts for 



10, and that of soda between 3 and 4 parts. 



DeeomposHich The. results of the decomposition of water by the bases of 



ot water by the ^-^^ alkalis were much more readily and perfectly obtained 



than tbbse of their combustion. 

 Amalgam of To check the rapidity of the process, and, in the case of 

 ^^■^^ °^ J^°'^^''^;potash, to prevent any of the basis from being dissolved, I 

 employed the amalgams with m-ercury. I used a known 

 weight of the bases, and inade the amalgams under naph- 

 "tha, using about two parts of mercury in volume to one of 

 'batsis. 



In the first instances I placed the amalgams under tubes 

 ^lled with naphtha, and inverted^ in glasses of naphtha, and 

 slowly admitted water to the amalgam at the bottom of the 

 glass; buL this preoautioa I soon found unnecessary, for the 

 '■'' action 



