OK AMMONIACAL PLATINUM BASES. 35 



Platinum 38, u 



Iodine 54, 60 



and the alkaline liquid gave with hydroiodic acid a black precipitate, containing 



Platinum 37,58 



Iodine 55, tia 



The two black powders consequently seem to have the same composition, which 

 agrees with the formula for the iodide of octo-platinammine. 



PtT.16NH 3 .I 18 . 

 This formnia requires: 



Platinum 38,?; 



Iodine 55,19 



These have been my researches on the derivates of the iodide of platinammine 

 and I regret my inability to give more positve facts, but still it would seem nearly 

 certain that by the action of alkalis upon the iodide of platinammine a yellow diplatin- 

 ammin-anhydro-iodidc is first formed, which by a prolonged action of the alkali 

 partially löses its iodine and is transformed into an anhydro-hydrate. When hydro- 

 iodic acid reacts upon this anhydro iodide, the hydroiodic acid is fixed and produ- 

 ces the iodide of diplatinammine, and this treated in the same manner yields the io- 

 dide of Tetraplatinammine, from which, by a similar synthesis, the iodide of octopla- 

 tinammine is formed. 



We would then have the following series: 



IV 



Iodide of Platinammine Pt . 2NH :i . 41 



VI 



" » Diplatinammine Pt, . 4NH 3 61 



» » Tetraplatinammine Pt 4 . 8NH 3 . 101 



XVIII 



» » O cto platinammine Pt 8 . 16NH., . 181 



These formulas consequently form a homoloqous series of the general expression 



Pt;(NH 3 ) 2n i 2n+2 . 



These derivates of the iodide of platinammine well merit a more complete exa- 

 mination, as the facts discovered by me only make it appear probable that the atoms 

 of platinum can fix another exactly as the atoms of carbon, but this is by no means 

 proved to be the case, especially as the uncrystalline form of the iodides, their inso- 

 lubility and the probably destroying action of concentrated hydroiodic acid upon them 

 make it rather uncertain, whether the products, I have analysed, really were pure che- 

 mical compounds or not. They may have been mixtures, but in this case the coinci- 

 dence of their composition with the formulas, which one would previously have ex- 

 pected them to have, is verv extraordinär}'. 



