OF ARTS AND SCIENCES. 27 



I. 0.2370 grm. of the substance gave 0.0578 grm. of silicic dioxide 

 and 0.1637 arm. of sodic fluoride. 

 II. 0.1 23G grm. of the substance gave 0.0841 grm. of sodic fluoride. 



Calculated for Found. 



(C U 5 NH,) 3 (SiF 4 ) 2 . (C G H NH,) 4 (SiF 4 ),. I. IL 



Silicon 11.50 9.65 11.39 



Fluorine 31.24 26.20 31.25 30.79 



In view of this decomposition of the dianiline silicotetrafluoride into 

 aniline and trianiline disilicotetrafluoride, and also of the formation of 

 the dianiline silicotetrafluoride by heating aniline with trianiline disili- 

 cotetrafluoride, there seems no doubt that the real formula of this 

 substance is (C 6 H.NH 2 ) 4 (SiF 4 ) 2 , that is, double the simplest formula 

 determined by analysis, and that the reaction for its spontaneous 

 decomposition is the following: 



(C 6 H 3 NH 2 ) 4 (SiF 4 ) 2 = C 6 H 5 NH 2 -t-(C 6 H 3 NH 2 ) 3 (SiF 4 ) 2 . 



Action of Fluoride of Silicon on other Bases. 



Triorthotoluidine Disilicotetrafluoride, (C 7 H 7 NH,) 3 (SiF 4 ) 2 . — This 

 substance was prepared by passing fluoride of silicon into a solution of 

 orthotoluidine in benzol, when a very heavy gelatinous precipitate was 

 formed, which was purified by washing with benzol and three sublima- 

 tions. It can be formed also by the methods given under the aniline 

 compound, but precipitation from a benzol solution gives the result 

 more easily, and furnishes a purer product. Its composition was deter- 

 mined by the following analyses. 



I. 0.2100 srni. of the substance £ave 0.0476 <*rm. of silicic dioxide. 



II. 0.3530 grm. of the substance gave 0.2177 grm. of sodic fluoride. 



III. 0.2330 grm. of the substance gave 0.1440 grm. of sodic fluoride. 



IV. 0.2050 grm. of the substance gave 0.1266 grm. of sodic fluoride. 



III. IV. 



27.97 27.94 



Properties. — It is a white powder subliming without melting or 

 decomposition, like the corresponding aniline compound. It dissolves 

 in hot common alcohol, and the solution deposits on cooling orthoto- 

 luidine fluosilicate in fine needles. 



Tri paratoluidine Disilicotetrafluoride (C 7 H.NH. 1 ).,(SiF 4 ).,. — This 

 substance was made and purified like the corresponding ortho com- 



