496 



Anisic acid. 



1st Stage C 16 H 8 O 6 + 2HSO 4 =C 16 H 8 S 2 O 12 +2HO. 

 2nd Stage C 16 H 8 O 6 + 4HSO 4 =C 14 H 8 S 4 O 14 +4HO+2CO 2 . 

 There can be no doubt that salicylic acid, so closely allied to anisic 

 acid, in fact, its homologue, a step lower in the system, must exhibit 

 a similar deportment. Mr. Baldwin Duppa has been occupied with 

 this subject in my laboratory, and has already obtained the first term, 

 the sulpha-salicylic acid, 



C 14 H 6 S 2 12> 



which forms extremely beautiful compounds. 



On submitting salicylic acid to the action of an excess of sul- 

 phuric acid, at a temperature of 180, the same phenomena present 

 themselves which are noticed in the case of salicylic acid, a powerful 

 evolution of carbonic acid ensues, and the solution now contains a 

 new sulphur-acid, which is crystalline. As yet Mr. Duppa has 

 not succeeded in obtaining this acid in a state of sufficient purity 

 for analysis, but it may be assumed, without much hesitation, that 

 it will be found to be 



Disulphophenic acid. . . . C 12 H 6 S 4 O 14 . 



IV. " On the Separation of Iodine, Bromine, and Chlorine, and 

 the comparative degree of Affinity of these Elements for 

 Silver; with some Analyses of their Combinations with 

 that Metal occurring in Chili." By FREDERIC FIELD, 

 Esq. Communicated by Dr. HOFMANN, F.R.S. Received 

 . June 5, 1857. 



Although both bromide and iodide of silver are decomposed by 

 the action of chlorine at an elevated temperature, yet chloride of 

 silver is completely decomposed by bromide of potassium, and both 

 the bromide and chloride of silver by iodide of potassium. Even 

 the action of hot strong hydrochloric acid has but little influence 

 upon the iodide of silver ; many days of continuous boiling 

 are necessary for its entire decomposition. I believe that it has 



