54 Messsrs. Perkin and Duppa on lodacetic Acid. 



admits of finite algebraic solution. For one of the roots of its 

 resolvent 



or 



/« + ^ouH"" ± «" s/a'^-\m . t - Sfl" = 0, 



is a rational function of another, and, if so, this sextic may be 

 solved by the process of Abel. 



4 Pump Coiut, Temple, E.G., 

 June 14, 1859. 



Note. Arts 55-59 were added by a postscript dated June 25, 

 1859. 



X. On lodacetic Acid. 

 By W. H. Perkin, F.C.S.; andB. P. Duppa, Esq.* 



WHILST studying the action of bromine on acetic acid, it 

 struck us naturally that we might succeed in replacing 

 the hydrogen of acetic acid, not only by bromine, but also by 

 iodine. We first attempted to produce the substitution by acting 

 on acetic acid with iodine at high temperatures ; but, proceed as 

 we would, we were unable to obtain any results, the iodine appa- 

 rently exercising but little action on this acid. A mixture of 

 iodine and acetic acid, on being heated to about 200° C. for a fort- 

 night in a strong sealed tube, gave a mixture of hydriodic acid 

 and charcoal as a result. We mention this to show how far we 

 carried the experiment of direct substitution. 



We have also tried to produce lodacetic acid by treating acetic 

 acid with chloride of iodine, but without success. 



Having been unsuccessful in the above experiments, it appeared 

 possible that we might obtain the acid in question by treating 

 chloracetic acid, bromacetic acid, or one of its compounds with 

 an iodide ; for this purpose we selected bromacetic ether and 

 iodide of potassium. 



On mixing equivalent proportions of bromacetate of ethyle 

 (diluted with three times its volume of alcohol) and finely- 

 powdered iodide of potassium, a reaction takes place, the liquid 

 gets slightly warm, and becomes yellow when exposed to direct 

 sunlight. After being digested at about 40° C. for a couple of 

 hours in the dark, it must be filtered from the bromide of 

 potassium which has formed, and which should be repeatedly 

 washed with cold alcohol. The filtrate, after having been sepa- 

 rated from the alcohol by distillation in a water-bath, and washed 



* Communicated bv tlie Authors. 



