[ 134 ] 



may be perforated, and the condenfer may be well plated or 

 tinned on the infide. 



But as glafs appears to be the moft unexceptionable material, 

 I have ordered an apparatus to be conftru£led entirely of glafs, 

 and have hopes that I fliall have it fo executed as not to admit 

 any thing elfe to come in contacfl with the gas. As the difficulty 

 of execution may however caufe a variation in my plan, 1 fhall 

 defer the laying it before the Academy till I get it accomplilhed 

 to my wlfh. Ingenious workmen may alfo be induced to con- 

 trive and execute fome apparatus which may anfwer the pur- 

 pofe, Ihould my ideas feem pradlicable to them or ufeful for 

 ■philofophic experiments. 



As difagreeable accidents might arife from the burfting of 

 the glafs veflel, an ingenious mechanical friend has fuggefted to 

 me the propriety of enclofing it in a ftrong copper cafe. It 

 may coufiil of two hemifpheres with a broad rim fcrewed to- 

 gether as in figure 2. 



