Prof. Williamson on the Atomicity of Aluminium. 395 



In an older and larger pig, to which the same quantity was 

 given, lithium after one hour was found in the hip and knee joints 

 very faintly ; in the aqueous humour of the eye very distinctly ; but 

 none was found in the lens, not even when half was taken for one 

 trial. 



Chloride of rubidium in a three-grain dose was not satisfactorily 

 detected anywhere. When 20 grains had been taken, the blood, 

 liver, and kidney showed this substance ; the lens when burnt all at 

 once showed the smallest possible trace ; the cartilages and aqueous 

 humour showed none, probably because the delicacy of the spectrum- 

 analysis for rubidium is very much less than that for lithium. 



A patient who was suffering from diseased heart took some lithia- 

 water containing 15 grains of citrate of lithia thirty-six hours before 

 her death, and the same quantity six hours before death. The crys- 

 talline lens, the blood, and the cartilage of one joint were examined 

 for lithium : in the cartilage it was found very distinctly ; in the 

 blood exceedingly faintly ; and when the entire lens was taken, the 

 faintest possible indications of lithium were obtained. 



Another patient took lithia-water containing 10 grains of carbo- 

 nate of lithia five hours and a half before death : the lens showed very 

 faint traces of lithium when half the substance was taken for one 

 examination ; the cartilage showed lithium very distinctly. 



I expect to be able to find lithium in the lens after operation for 

 cataract, and in the umbilical cord after the birth of the foetus. 



I am, yours truly, 



H. Bence Jones. 



February 9. — Major-General Sabine, President, in the Chair. 



The following communication was read : — 



" Note on the Atomicity of Aluminium." By Professor A. W. 

 Williamson, F.R.S., President of the Chemical Society. 



In the " Preliminary Note on some Aluminium Compounds," by 

 Messrs. Buckton and Odling, published in the last Number of the 

 Society's ' Proceedings*,' some questions of considerable theoretical 

 importance are raised in connexion with the anomalous vapour- 

 densities of aluminium ethyle and aluminium methyle. The authors 

 have discovered that the vapour of aluminium methide (Al 2 Me 6 ) 

 occupies rather more than two volumes (H=l vol.) at 163°, when 

 examined by Gay-Lussac's process, under less than atmospheric 

 pressure. The boiling-point of the compound under atmospheric pres- 

 sure is given at 130°, and the compound accordingly boiled a good 

 deal below 130° at the reduced pressure at which the determination 

 was made. The vapour was therefore considerably superheated when 

 found to occupy a little more than two volumes. When still further 

 superheated up to 220° to 240°, it was found to possess a density 

 equivalent to rather less than four volumes at the normal tempera- 

 ture and pressure. 



The aluminium ethyle was found to have a density decidedly in 

 excess of the formula Al 2 Et 6 = 4 vols., but far too small for AP Me 6 

 = 2 vols. From their analogy to aluminic chloride, A1' 2 CF = 2 vols., 



* See also pp. 313 and 316 of the present volume of this Journal.. 

 2D2 



