1865.] Messrs. Buckton and Odling on Aluminium Compounds. 19 



at 74- 5 C. Numerous analyses furnished the numbers required by the 

 formula 



OH 



Leucate of silver was made by adding oxide of silver to a hot solution of 

 the acid. After filtration and evaporation in vacua, it crystallizes in 

 brilliant silky fibres adhering closely to the capsule. These are anhydrous, 

 and are scarcely discoloured by prolonged exposure to a temperature of 

 100 C. They yielded on analysis numbers closely corresponding with 

 those calculated from the formula 



Although this acid possesses the same percentage composition, atomic 

 weight, and fusing-point as the leucic acid obtained by the action of 

 zincethyl upon oxalic ether, yet it does not appear to be identical with that 

 acid. The silver-salt of the latter crystallizes in brilliant needles radiating 

 from centres standing up freely from the capsule, and containing half an 

 atom of water which is not expelled at 100 C. This salt also further 

 differs from that above described by becoming rapidly discoloured when 

 exposed to the heat of a steam-bath. We are at present engaged with a 

 rigorous comparison of the properties of these and other similarly related 

 acids of the lactic series. 



III. " Preliminary Note on some Aluminium Compounds." By 

 GEORGE BOWDLER BUCKTON, F.R.S., and WILLIAM ODLING, 

 M.B., F.R.S. Received January 12, 1865. 



Until recently the molecule of aluminic chloride had always been repre- 

 sented by the formula A1 2 C1 3 , or, selecting the high atomic weight of alu- 

 minium, as required by its specific heat, Al C1 3 . But since Deville's deter- 

 mination of the vapour-densities of aluminic and ferric chlorides, many 

 chemists of eminence, both in this country and abroad, have adopted the 

 formula A1 2 C1 6 , and have consistently doubled the previously received for- 

 mulae for the entire series of aluminic compounds. In our opinion, how- 

 ever, the hitherto existing data seemed hardly sufficient for the definitive 

 establishment of either set of formulae ; and it occurred to us that an exa- 

 mination of the so-called organo-compounds of aluminium might not im- 

 probably throw some important light upon the question at issue between 

 them. We regarded the determination of the question as a matter of con- 



c 2 



