198 



NA TURE 



[Dec. 2j, il 



including the three groups, more than 1200 ladies attended the 

 Manchester meeting, instead of 493 only. Again, of the ladies 

 at the recent Bath meeting, there were 84 members, fhis 455 

 associates, fins the, to me, unknown number who took "ladies' 

 tickets." Wm. Pekgelly. 



Torquay, December 18. 



On the Formulas of the Chlorides of Aluminium and 

 the Allied Metals. 



In recent numbers of Natukk there have appeared several 

 interesting accounts of determinations of the vapour-densities of 

 certain metallic chlorides. According to the views generally 

 held by chemists, the molecules of some of these chlorides should 



be represented by the general formula M.,Cl8, but conclusions 

 are drawn from the experiments described (l) that the formula 

 MCI3 is applicable to all these chlorides ; (2) that the chlorides 

 of the formula MoCl^ are probably incapable of existence in the 

 gaseous state, and that this formula should therefore be given 

 up ; (3) that the lower chlorides of these metals should be 

 expressed by the general formula MCl^ instead of M2CI4, 

 chlorides corresponding to the second formula being incapable 

 of existence. 



In view of the great interest that is felt in this question at the 

 present time, it seemed to me that a tabulated statement of the 

 results obtained by various chemists would be of value, in 

 order that a comprehensive view of the question might be 

 obtained : — 



Vapuur-Densitifs (Air = i) of Chlorides, &c. 

 Aluminium chloride : M.P. 187°; B.P. 183°. Calc. j ^j^^'fi ^ ^'s,. 



440 



18-62 



Aluminium bromide ] « 1 d^ o - 



( AigtJrg = 15-4. 



I Dumas | Deville and Troost 



I I atm. I 



27-00 



Aluminium iodide 



AII3 

 ALL 



I Dainas | Deville and Troost 



234 

 235 

 258 

 310 

 350 



Aluminium ethyl : B.P, 194°. 



4-5 



8-0 4-8-2 = 8-1 



6-0, 6-3, 6-4 = 6-2 



2-5 \ 



2-5 J 



V. Mejer 



A1(CJI.,)3 = 3-93. 

 Al.,(C.H5)«=7-86. 



Giy Lussac 1 Buckton and Odling 



Louise and Roux 



Complete decomposition 



Louise and Roux obtained results agreeing with the formula AlgCCjHg)^ by Raoult's freezing-point method, employing 

 ethylene dibromide as solvent. 



