ACHIEVEMENTS OF CHEMICAL INDUSTEY — DUISBEKG. 239 



SULPHURIC ACID. 



The triumphal progress of the contact process for the manufacture 

 of sulphm-ic acid in the United States scarcely has its parallel in 

 Germany, where it originated. Platinum, in spite of the fact that 

 its price has increased threefold, is still our principal contact agent. 

 As it is possible to carry out other contact processes with various 

 contact mateiials, wo shall certauily find olner agents than plati- 

 num available for sulphuric acid anhydride. It ought therefore to 

 be a fruitful field for research to find cheap substitutes for plati- 

 num. The Americans in the 20 years that have elapsed since 

 Kmetsch first successfully carried out the contaci process, have 

 increased their output threefold for the same weight of platinum. 

 Nevertheless, the old lead-chamber process still competes with the 

 new method, and the steady improvement of this process and the 

 purity of the resulting acid must be acloiowledged. In fact, the 

 lead-chamber process promises to make further j^rogress in the 

 future in view of the success of Falding's high cham])ers and Opls 

 towers, in which large quantities of acid flow down. 



The Gaillard tower is supreme for concentration and recovery 

 of the acid and for the regeneration of the various w^aste acids. 



AMMONIUM SULPHATE. 



A new way of manufacturing sulpuhric acid, together with am- 

 monia, from the gases which are produced by the dry distillation of 

 coal, is looming above the horizon. Burkheiser is seeldng, with 

 the aid of especially prepared wet iron compounds, to bmd the 

 sulphur, simultaneously absorbing cyan, and to convert the ammo- 

 nium sulphite thus produced into ammonium sulphate by oxidation 

 with atmospheric air. 



In competition with Burkheiser, Walter Fekl is endeavoring to 

 recover sul]:)luir directly as ammonium sulphate by a series of inter- 

 esting reactions, in wliich thiosulphates play an important part. 

 Such plants are in operation in Konigsberg and here in New York. 



NITROGEN COMPOUNDS. 



So much has been written concerning the progress made m the last 

 five years in the utilization of atmospheric nitrogen that I need not 

 enter into a descrij)tion of Birkeland-Eyde's, Schonherr's or Pauling's 

 process for the direct oxidation of nitrogen by means of tlie electrical 

 discharge, nor of Frank-Caro's method of forming cyanamido from 

 carbides [the world ])ro(hiction of cyanamide is, according to Dr. N. 

 Caro, 120,000 tons per year, of which 31,000 tons are manufactured 

 in Germany (16,000 in Trostberg and 15,000 m Knapsack near 



