26 PROCEEDINGS OF THE AMERICAN ACADEMY 



while to try to purify the residual substance for analysis. Ethylbro- 

 tuide acted in the same way, but with more difficulty. Strong sulphu- 

 ric acid decomposes trianiline disilicotetrafluoride, giving off fluoride 

 of silicon. The action of the other common reagents with this sub- 

 stance could not be studied, because it is decomposed by water or 

 alcohol. 



Dianiline Silicotetr a fluoride, (C G H 5 NH 2 ) 4 (SiF 4 ) 2 . — This substance 

 was formed when aniline vapor was conducted into a receiver filled 

 with fluoride of silicon, in the hope of preparing a compound contain- 

 ing a larger proportion of fluoride of silicon than that in the substance 

 just described. The fact that, on the contrary, a body richer in aniline 

 is formed, is probably to be accounted for by the high temperature at 

 which the union of the two substances took place ; and this view is 

 confirmed by some experiments in which we heated the trianiline 

 disilicotetrafluoride with one molecule of aniline to 150° in a sealed 

 tube for about five hours : the product was a purplish mass, which gave 

 results on analysis showing that a considerable quantity of aniline had 

 been taken up, although not quite enough to convert the trianiline 

 disilicotetrafluoride completely into the dianiline silicotetrafluoride. 

 As the substance prepared directly from aniline and fluoride of silicon 

 could not be purified on account of its slight stability, it was analyzed 

 in the crude state with the following results, which are as accurate as 

 could be expected under these circumstances. 



I. 0.3803 grm. of the substance gave 0.0826 grm. of silicic dioxide 

 and 0.2255 grm. of sodic fluoride. 

 II. 0.3032 grm. of the substance gave 0.0645 grm. of silicic dioxide 

 and 0.1798 grm. of sodic fluoride. 



Properties. — It is a white powder which cannot be sublimed, as it 

 decomposes with blackening when heated. With water it is decom- 

 posed and dissolved with deposition of silicic acid. It is possessed of 

 but slight stability, as it gradually decomposes spontaneously even 

 when kept in a corked tube at ordinary temperatures, the substance 

 turning yellow and giving up aniline, which was extracted with ligro- 

 ine, and recognized by its smell and its characteristic color with 

 bleachiug-powder, while the residue was pure trianiline disilicotetra- 

 fluoride, as shown by the following analyses. 



