166 Professor Apjohn on a new Compound. 



hermetically sealed, so as effectually to prevent the volatilization of iodine. 

 Agitation was now resorted to, and a gentle heat at the same time applied, 

 which caused the separation of the oil, the iodine previously combined with it 

 having entered into union with the zinc, and formed with it a salt dissolved by 

 the water. The tube was now broken, and its contents having been thrown 

 upon a single filter previously deprived of all soluble matter, distilled water was 

 poured on until the entire of the iodide of zinc was carried through. The wash- 

 ings were concentrated, suffered to cool, and then treated with the equivalent 

 quantity of nitrate of silver, and the resulting precipitate (iodide of silver) 

 having been, as in the previous experiment, sparingly washed with cold water 

 containing a little ammonia, was dried and weighed. From this the total quan- 

 tity of iodine in the compound, both that combined with potassium and with the 

 oil, was collected. But the quantity in the former state having been already 

 ascertained, the difference is the iodine associated with the oil. 



In an experiment thus conducted 6.55 grains of the substance yielded of 

 iodide of silver 4.52 grains, equivalent to 37.20 grains of iodine for 100 of the 

 compound. Subtracting from this 9-58, the iodine of the iodide of potassium, 

 we obtain, as the representative of the amount of this element associated with the 

 oil, the number 27.62. Hence 



^±^1:^ = 28.14 



is the mean amount of the iodine in the latter state of combination as derivable 

 from both experiments. But 



28.14 



y.33 



= 2.93, or q. p. = 3. 



We thus arrive at the conclusion, that for every atom of iodide of potassium in 

 the substance under consideration there are three atoms of iodine in combination 

 with the oil of cinnamon. 



Before leaving this branch of the analysis I may observe, that the iodine of 

 the oil may be directly obtained by decomposing the compound in a glass tube at 

 a red heat in contact with lime, and acting upon the residue with water, which 

 dissolves the iodide of calcium, and along with it a little lime. The latter being 

 separated in the usual manner by carbonic acid and boiling, the former may be 



