1874.] History of the Or tins. 55 



heated. It is much more soluble in water than iodorcin, and is very 

 soluble in alcohol or ether ; hot benzol dissolves it readily ; but it is only 

 slightly soluble in carbonic disulphide. When heated with nitric or sul- 

 phuric acid, it behaves like iodorcin. 



The analytical results were obtained from the compound dried in 

 vaciw, at the ordinary temperature. 



I. '343 gramme substance gave *341 gramme argentic iodide. 



II. '357 gramme substance gave '354 gramme argentic iodide. 



III. -265 gramme substance gave -298 gramme carbonic anhydride 

 and -053 gramme water. 



Theory. I. II. III. 



C 6 = 72 30-51 30-67 



H fl = 5 2-12 2-22 



I = 127 53-81 53-73 53-58 



O a = 32 13-56 



236 100-00 



The numbers agree with the formula C 6 H 6 1 O a . 



In preparing teriodorcin by the action of iodine protochloride on orcin, 

 it was observed that a comparatively large amount of the dilute solution 

 of iodine chloride could be added to the aqueous solution of orcin before 

 a permanent precipitate of teriodorcin was produced. It seemed possible 

 that an intermediate iodine derivative was first formed, far more soluble 

 than the teriodorcin, and which subsequently became converted into the 

 latter by the further action of the chloride of iodine. In order to as- 

 certain whether this was actually the case, a dilute solution of iodine 

 protochloride was added to an aqueous solution of orcin containing one 

 part of orcin in fifty of water, as long as the precipitate redissolved in 

 the liquid on agitation. The addition of iodine was then stopped, and 

 the filtered solution agitated with ether. The ethereal solution, on 

 evaporation, left an oily uncrystallizable liquid which was readily soluble 

 in water, and which evolved iodine when heated with concentrated sul- 

 phuric acid : this liquid, on standing some days, deposited a few crystals 

 of unaltered orcin. 



I cannot conclude this paper without acknowledging the very efficient 

 aid I have received from my assistant, Mr. Charles Edward Groves, in 

 conducting this investigation. 



