432 RECORD OF SCIENCE FOR 1887 AND 1888. 



not exist in the gaseous state. For chronious chloride the data give a 

 density considerably too high for CrClo; but the compound vaporizes 

 Avith diiJiculty, and tbe density diminishes with rise of temperature. 

 CrClo is probably the true formula. (Jouru. Chem. Soc, liii, 828.) 



GaUium. — According to Nilsou and Petterson the trichloride of this 

 metal has a vapor density which at 350° is 8.84G, at 606° is 6.144, and 

 at 1,000-1,100° is 5 J85. GajCle requires 12.10. GaCls requires 0.08. 

 The latter value is probably correct. They also describe a dichloride 

 whose vapor density agrees with the symbol GaOL. (Journ. Chem. 

 Soc, LIII, 822.) 



\n this case also Nilson and Petterson are partly controverted by 

 Friedel and Crafts, who find the tri-chloride of gallium, as measured at 

 273°, to be GagCle- Above this temperature it begins to dissociate, per- 

 haps into 2 GaClj. (Compt. Pcud., cvii, 306.) 



For indium, Nilson and Petterson re-examined the trichloride, and 

 also describe two new compounds, a mono- and dichloride, respectively. 

 The vapor densities of the three compounds indicate molecules of InCls, 

 IuCl2, and InCl. (Journ. Chem. Soc, liii, 816.) The density of the 

 trichloride is also gi^'tin by Biltz, who tiuds it concordant with luCls. 

 (Berichte, XXI, 2760.) All of the foregoing data relative to the n^on- 

 aluminum group are well summarized by Sydney Young, who gives 

 them in tabular form in Nature for December 27, 1888. His note is 

 discussed by Brauner in the same journal for January 31,1889. 



The vapor density of tellurium tetrachloride has been studied by 

 Michaelis. It boils at 380°, and up to 448° it distills undecomposed. 

 Even at 530 it is scarcely dissociated at all, and its density indicates a 

 molecule of TeCl4. Hence tellurium is at least quadrivalent. (Berichte, 

 XX, 1780.) 



Befrigeraiing mixtures. — The freezing mixtures containing solidified 

 carbon dioxide have been carefnlly studied by Cailletet and Colardeau, 

 who give the following determinations of temperature : 



° c. 



Solid carbon dioxide — 60 



Solid carbon dioxide in vacuo — 76 



Solid carbon dioxide in ether — 77 



Same mixture iu vacuo - 103 



The following all represent ordinary pressures : 



o 



Solid carbon dioxide in methyl chloride —82 



Solid carbon dioxide in sulphur dioxide # —82 



Solid carbon dioxide in amyl acetate —78 



Solid carbon dioxide iu phosphorus trichloride —76 



Solid carbon dioxide iu absolute alcohol —72 



Solid carbon dioxide in ethylene chloride — 60 



In the three compounds last named the carbon dioxide was manifestly 

 less soluble than in the others. Hence a smaller r«'duction of tempera- 

 ture as compared with that ot the original solid. (Compt. Kend., cviii, 

 1631.) 



