of the Cacodyl Series. 387 



dicals, which is now rendered perfectly incontrovertible by 

 the power of this radical to form directly the compounds 

 from which it was separated. The whole series of com- 

 pounds already considered can be formed either in the di- 

 rect or in the indirect way, and the conditions under which 

 this happens are precisely those observed with regard to the 

 metals. The indirect action of oxygen, as well as the action of 

 most of the oxidizing agents, occasions an increase of tempe- 

 rature in the formation of both the oxide and the acid of this 

 radical ; and from the first, by the action of hydracids, we 

 obtain the corresponding combinations with sulphur, selenium, 

 tellurium, chlorine, iodine, bromine, and cyanogen. By the 

 treatment of the so-formed chloride with chloride of copper, 

 chloride of platinum, chloride of palladium, &c., certain dou- 

 ble chlorides are formed, which I intend to refer to hereafter. 

 When the radical is dissolved in nitric acid, and nitrate of 

 silver is added, a very considerable precipitate is produced in 

 the form of regular octahedral crystals, consisting of a combi- 

 nation of the latter salt with oxide of cacodyl, which appears 

 to act the same part as constitutional water in salts. A solu- 

 tion of corrosive sublimate occasions the immediate formation 

 of an oxychloride in the form of fine silky crystals, composed 

 of 1 atom of oxide of cacodyl combined with 2 atoms of chlo- 

 ride of mercury. 



Oxidizing agents are not the only bodies which act in a 

 direct manner; other combinations are also formed in the 

 same way. Sulphur in small quantities is acted upon by the 

 radical, being dissolved by it, and forms a clear solution pos- 

 sessing all the properties of sulphuret of cacodyl, producino- 

 with solutions of oxides of lead and silver, sulphurets of these 

 metals, and sulphuretted hydrogen with acids. Upon the ad- 

 dition of a large quantity of sulphur a higher sulphuret is 

 formed, which is solid, and soluble in aether ; from which latter 

 solution it may be obtained in fine crystals. When to cacodyl 

 a solution of chlorine is added, its yellow colour is immedi- 

 ately destroyed, together with its bleaching power; chloride of 

 cacodyl is formed, which, acted upon by acids, gives hydro- 

 chloric acid. All these reactions, to which many more might 

 be added of a not less striking nature, prove that this radical 

 acts the part in every instance of a simple electro-positive ele- 

 ment, and that it is in fact a true organic metal. 



3. Decomposition of the Radical. 



When the radical is distilled with anhydrous chloride of 

 zinc it is decomposed, and forms several compounds at differ- 

 ent temperatures. In order to ascertain more precisely the 

 2D2 ^ 



