20 



beo'iiinings ; he arranged for a very extensive set of experi- 

 ments to be made so as to fix on a standard of comparison, 

 but has not found time. 



" On some some i)oints in the Chemistry of Acid Manu- 

 facture," by H. A. Smith, F.C.S. 



The author endeavours to throw some Ught on the interior 

 economy of the lead chamber as at present used in the 

 manufacture of sulphuric acid, by making first : — 



An expermiental examination of the causes tvhich deter- 

 mine the action, inter se, of the gases in the lead chamber. 



The conclusion come to differed from that generally 

 received. He believes that action can take place between 

 dry sulphurous acid and nitric acid gases, without the use 

 of steam, and showed by several experiments that if action 

 be commenced between the above mentioned gases it con- 

 tinues, even in the absence of air, till all the available 

 oxygen present in the nitric acid has been made use of 



He also comes to the following conclusions : — 



1. That the Aolume of steam introduced should be less 



than the combined volumes of the two gases. 



2. That the volume of steam introduced should increase 



in proportion to the increase of temperature. 



3. That the greatest amount of action between the two 



gases (and therefore the greatest }'ield of vitriol) 

 takes place near the surface of previously formed 

 sulphuric acid, and that therefore in ' starting' the 



