Dr. Hofmann ow Chloranil. 205 



yield chloranil. This is the case also with nitrobenzoic acid, 

 benzine, nitrobenzide, binitrobenzide, and hydruret of ben- 

 zyle (oil of bitter almonds). 



It yet remained to try the preparation of chloranil from sali- 

 cine, the basis of all the salicyle compounds, when indeed the 

 anticipated transformation occurred. This decomposition is 

 readily comprehended, if it be remembered that the salicine 

 contains the elements of 3 eqs. of salicylous acid and 10 eqs. 

 of water, e.g. 

 C,2H2s,0„2 + 24C1+ 180 = 3(Ci2Cl O4) + 6CO2 +16 HO + 12HCI. 



Salicine. Chloranil. 



The salicine is, on account of its solubility in water, perhaps 

 the fittest substance for yielding large quantities of chloranil ; 

 it is only requisite to dissolve salicine and chlorate of potash in 

 boiling water and to add at intervals small quantities of hydro- 

 chloric acid. By degrees the mixture assumes a deep orange 

 yellow colour, which is followed by a violent reaction ; and be- 

 sides the products of decomposition resulting from the chloric 

 acid, there escapes a large portion of carbonic acid, and the 

 surface of the liquid becomes covered with a thick layer of 

 sulphur-yellow crystals of chloranil. 



The salicine must not be treated with hydrochloric acid and 

 then the crystals of chlorate of potash added, for the acid will 

 transform the salicine into salicetine, which cannot be resolved 

 into chloranil. Even by a long-continued boiling of the sali- 

 cetine with the oxidizing mixture, nothing is obtained but a 

 yellow uncrystalline mass insoluble in water and alcohol. 1 

 have made a burning of the chloranil procured from salicine 

 and obtained the following numbers : — 



0"373 grm. of chloranil gave 0*414' grm. of carbonic acid 

 = 30*27 per cent. 



Neither phloridzine, phloretine, cumarin, nor cinnamic acid, 

 are transformable into chloranil. The first three furnish, by 

 the action of chlorate of potash, yellow resinous bodies in- 

 soluble in water but soluble in alcohol, while the last is con- 

 verted into a colourless oil, to which I shall recur in a future 

 paper. It is almost superfluous to remark, that if chloranil is 

 prepared from isatine, chlorisatine or bichlorisatine, the trans- 

 formation takes place quicker and more completely by the 

 employment of a mixture of hydrochloric acid and clilorate of 

 potash than by conducting a stream of chlorine through the 

 alcoholic solution, for in a few minutes the conversion of con- 

 siderable quantities is effected. Anthanilic acid also naturally 

 suffers the same decomposition. 



C,4H7N04+ 40 + 8Ci = C12CI4O4+ 2CO2 + NH3+4HCI. 



