M. Bauer on Hydride of Amyle. 379 



upper a colourless glass, and the lower an opake white mass. In 

 the clear glass and on the sides of the crucible there were inter- 

 spersed individual brown crystals, which were left undissolved 

 when the whole mass was treated with hydrochloric acid : the 

 white mass also left after this treatment a heavy hard powder, 

 seen under the microscope to consist of crystals like the larger 

 ones. 



A crystallographical examination of the larger crystals was 

 made. Though small, they were frequently found as well deve- 

 loped as the most perfect crystal models. Their form was that 

 of a dimetric prism with a pyramid. Hence, if this is correct, the 

 oxide of thorium is isomorphous with oxide of tin and titanic 

 acid. It is a binoxide, ThO 2 , and not ThO and Th 2 3 , as has 

 hitherto been supposed. 



A similar experiment was made with tantalic acid, by fusing it 

 with microcosmic salt under the same circumstances. The slag 

 contained a crystalline powder consisting of tantalic acid, besides 

 some individual larger needles of the same substance, the form of 

 which on examination was found to be that of a rhombic prism* 



In his researches on oxide of amylene*, Bauer obtained hy- 

 dride of amylene as an accessory product in the preparation of 

 amylene. It is not possible to separate these sul?stances by frac- 

 tional distillation, as their boiling-points are too near; but by 

 acting on the mixture with bromine, bromide of amylene, 

 € 5 H 10 Br 2 , is formed, while hydride of amyle remains intact. 

 Bromide of amylene boils at 170°, and hence the latter body is 

 readily separated by fractional distillation. 



When chlorine is passed into hydride of amyle, a brisk action 

 is set up, the gas is absorbed, hydrochloric acid gas is liberated, 

 and considerable heat is disengaged. The first product of the 

 action is chloride of amyle, € 5 H n Cl; when this body, which 

 boils at 102°, is separated by fractional distillation, and chlorine 

 gas passed into the residue for several hours, the liquor becomes 

 very thick : when it is distilled it begins to boil at 180°, and 

 the thermometer rises quickly to 230°, and remains for some 

 time between this point and 240°. It afterwards rises to 300°, 

 and then decomposes, leaving a black residue. The body which 

 distils between 230° and 240° has the formula G 5 H 8 CI 4 , and is 

 the chloride of trichlorinated amyle formed in accordance with 

 the equation 



€ 5 H 12 + 8C1=G 5 H 8 C1 4 + 4HC1. 

 It is a colourless liquid insoluble in water : it is heavier than 



* Phil. Mag. vol. xx. p. 44. 

 2C2 



