ON THE BASI OF FOTASH. 307 



which might easily be forgiven, if they were the only errours 

 that have been committed in the essay. 



I am, SIR, 

 Your obedient humble servant, 

 3 March, 1808. DYTISCUS. 



See errata at the foot of the last page. 



XII. 



Farther Experiments and Observations on Potash and its Base. 

 In a Letter from Mr. C. Sylvester, 



To Mr. NICHOLSON, 

 Dear Sir, Derby, March 28th, 1808. 



J N your Journal for February of this year, I communica- Detonating 

 ted an account of some experiments, made, in company with ducec? frorn^ 

 my friend Mr. James Oakes, with a view to produce the me- potash, 

 tallic base of the alkalis, discovered by Professor Davy. In 

 consequence of our not having sufficient galvanic power at 

 that time, we did not succeed in separating the globules of 

 metal from the potash, although we produced a substance, 

 which detonated with a bright flash, when presented to wa- 

 ter. We have however since repeated the experiments, with Completely se. 

 increased power, and have completely succeeded in producing para e rom 

 the metal, detached from the alkali, in which it is imbedded. 

 The result of these additional experiments I should, accord- 

 ing to promise, have communicated for insertion in the suc- 

 ceeding number of your Journal; but, observing, both in 

 your, and other periodical works, that the same result had 

 been obtained by others, I conceived any farther detail un- 

 necessary: as however wc have paid attention to the pro- 

 duction of the black matter alluded to in my last, which ap- Black matter 

 pearance has not been observed by any other experimen- accom P an > in 8 

 talist, I have thought proper to make a few additional re- 

 marks. 



After repeating the experiments several times, we ascer- Formed at the 

 tained tho curious fact, that the black matter was lormed at JJJP r 

 X 2 the 



