Development of the Chemical Industry 7 



natural deposits in the soda lakes in western States, then 

 we may have soda for the digging of it. 



With the replacement of the LeBlanc process by the 

 ammonia soda process we lost the by-products of the 

 former, which in time had become valuable and neces- 

 sary for the purpose of making chlorine. But the elec- 

 tro-chemical decomposition of brine into sodium, chlo- 

 rine, and hydrogen has met the emergency, and today 

 we have large electro-chemical plants near Niagara Falls 

 which make caustic soda and chlorine in quantities to 

 satisfy our wants. And I have also heard of a process 

 for making synthetic hydrochloric acid from chlorine 

 and hydrogen, this reversing the former mode of manu- 

 facture. The chamber process for making sulphuric 

 acid, which first was developed on a large scale in con- 

 nection with the LeBlanc soda process, has experienced 

 a similar transformation. The chamber process makes 

 cheap sulphuric acid of moderate strength. If greater 

 strength than 60° Be. or 75% acid was required, it was 

 formerly necessary to concentrate the weak acid in plati- 

 num vessels at great expense, and fuming sulphuric acid 

 was obtained by the distillation of sulphate of iron at 

 great cost. Today we make sulphuric acid by the con- 

 tact process and the mode of working is reversed. We 

 make sulphuric acid anhydride first and dilute it with 

 water to make the weaker grades. To make sulphuric 

 acid we need sulphur as raw material. This we had to 

 buy from Sicily, or we used pyrytes, a combination of 

 sulphur with iron, which we imported from Spain. In 

 most recent times Hermann Frasch showed us a way to 

 recover sulphur which we knew to exist in Louisiana 

 deep down in the earth. He built large steam plants, 

 blew superheated steam through a double pipe down to 

 the sulphur deposits, melted the sulphur, and forced the 

 molten sulphur out through the other pipe to the sur- 

 face of the earth. Tlie supply seems to be inexhaustible, 

 and we command the supply of the world. The sul- 

 phuric acid industry has often been referred to as a 



