12 WILLIAM GOSSAGE 



would be by means of carbonic acid'' This 

 conclusion was not arrived at without long 

 years of patient experiment. His patents at 

 one time indicating that his hopes rested 

 on muriatic acid, and at another time on 

 sulphurous acid, but his first thought was his 

 last thought, and, as Mr Chance proved, was 

 his right thought. 



The patent of 1837 states "as to that part 

 of my invention, which relates to the use of 

 the alkali residuum, which, as I have stated, 

 contains sulphuret of calcium and carbonate 

 of lime, when this residuum is acted upon by 

 muriatic acid, a mixture of sulphuretted hydro- 

 gen gas and carbonic acid gas is evolved, 

 these mixed gases being placed in contact 

 with another portion of alkali residuum, the 

 carbonic acid reacts on the sulphuret of 

 calcium and liberates therefrom a further 

 quantity of sulphuretted hydrogen. 

 Carbonic acid being thus absorbed and ab- 

 stracted from a mixture of gases, sulphuretted 

 hydrogen is obtained nearly free from carbonic 

 acid gas, and in a state favourable to undergo 

 combustion, and thereby produce sulphurous 

 acid. Instead of obtaining sulphuretted 

 hydrogen from alkali residuum by means 

 of muriatic acid he says I sometimes use 



