SCHLOESING' s MODIFICATION OF SERULLAS' PROCESS 579 



Kraut, 58 and Bertrand. 59 The method was fully developed by a 

 committee appointed by the French agricultural chemists in iSS/. 60 



Wense has also described an improved method of estimating 

 potash as perchlorate after the removal of sulfuric acid and also 

 a process of preparing perchloric acid by distilling potassium per- 

 chlorate with sulfuric acid in a vacuum. 61 He was also the first 

 who proposed the plan of rendering potassium perchlorate in- 

 soluble in alcohol by dissolving a little perchloric acid therein. 

 The best approved methods now known of preparing the per- 

 chloric acid and conducting the analysis will be described in the 

 following paragraphs. 



488. Schloesing's Modification of Serullas' Process. Dumas 

 called attention to certain phenomena which took place at Cher- 

 bourg in consequence of flooding a large portion of land with 

 sea water as a means of defense during the Franco-German war 

 and the effect which this flooding had upon subsequent vegeta- 

 tion. 62 Peligot was also interested in the discussion. Chevreul 

 called attention to the difficulty which he had experienced in 

 determining potash and soda, or rather the chlorids of potash 

 and soda, by means of platinum chlorid. 



In view of this difficulty, Schloesing proposed the use of 

 perchloric acid, which he states was first proposed by 

 Serullas who was negligent in not citing in his paper 

 the data of analysis which are the most efficacious means of 

 determining the merits of a method. 03 The chief cause of the 

 failure of the method proposed by Serullas is the difficulty of 

 getting perchloric acid in sufficient quantities and in 

 a pure state. To Roscoe is awarded the credit of hav- 

 ing devised a means of procuring the acid in abundance 

 and in a state of purity. The process of Serullas, according to 

 Schloesing, is one of the most precise when pure perchloric acid 

 furnished by the perchlorate of ammonia is employed. The 

 method proposed for conducting the analysis is as follows: In 



58 Zeitschrift fiir analytische Chemie, 1875, 14 : 152. 



59 Moniteur scientifique, 1881, 23 : 961. 



60 Grandeau, Traite d' analyse des matieres agricoles, 3rd Edition, 1897, 

 1 : 419. 



61 Zeitschrift fiir angewandte Chemie, 1891, 4 : 691 ; 1892, 5 : 253. 



62 Comptes rendus, 1871, 73 : 1080. 



63 Comptes rendus, 1871, 73 : 1269. 



