402 Prof. Bunsen on Cacodyl Corn-pounds containing Platinum. 



and this water can be replaced by oxides of metals. If we 

 remove this atom of water in the formula, we have remaining 

 one atom of oxide of platinum, and one atom of cacodyl, 

 which will explain the formation of these compounds in the 

 simplest manner. The I'ational expressions may be thus 

 given : — 

 For the anhydrous chlorine compound Pt O Ka + CI 



For the hydrous ... ... H O Pt O Ka + CI 



For that containing ammonia . , . . . N Hg Pt O Ka + CI 



For the oxide H O Pt O Ka + O 



For the sulphate (HOPtOKa+0) SO3 



The nature of this composition proves that the power of 

 inorganic acids to unite with certain organic bodies, without 

 losing their power of saturation, is not alone possessed by 

 acids, but that bases have also the same property ; for in the 

 present case, the oxide of platinum bears a relation to the 

 oxide of cacodyl similar to that which sulphuric acid does to 

 benzoic acid in sulpho-benzoic acid. In the latter, the ben- 

 zoic acid is as little indicated by reagents as the oxide of pla- 

 tinum in the cacoplatyl ; and as the double acid referred 

 to neutralizes only one atom of base, so the double base in 

 question saturates only one atom of acid, or that quantity 

 which the quantity of oxygen in the oxide of platinum indi- 

 cates. 



A comparison of this new class of compounds with that 

 discovered by Gros and Reiset, will afford another reason for 

 admitting the constitution which has been assigned to them. 

 Reiset has rendered certain the existence of a body, composed 

 of the elements of 1 atom water, 2 atoms ammonia, and I atom 

 oxide of platinum, which does not lose its atom of water when 

 it enters into combination with oxygen acids, and contains, 

 precisely as cacoplatyl, 2 atoms of oxygen, and saturates 1 atom 

 of acid. Berzelius affirms that these salts contain the oxide 

 of ammonium. Here ammonia is combined with the oxide of 

 platinum, as the naphthaline is in sulpho-naphthalic acid, viz. 

 {PtONH3,NH4 + 0)S03. 



The simple relation in which this salt stands to the caco- 

 platyl compound must therefore not be passed over. The 

 latter is nothing else than such a salt, in which the ammo- 

 nium is replaced by cacodyl. Its relation to ammonium in 

 the electrical series of compound radicals is like that of an 

 electro-negative metal to an electro-positive one, as, for in- 

 stance, iron to potassium. It cannot, however, be denied, 

 that, while the compound of Reiset is a strong caustic base, the 

 oxide of cacoplatyl forms only salts of an acid reaction. The 

 analogy whicih the vegeto-alkalies and their composition show 



