Mr. Grove on a new Voltaic Battery of great e7iergy. 287 



a pale brick-red colour, and gives salts of a red amethystine 

 hue. It has also two isomeric conditions distinctly defined. 

 Lantanium is reducible by potassium only from its combina- 

 tion with chlorine. It is apparently a gray, soft, ductile metal, 

 which oxidizes at the expense of water, and gives a hydrate 

 having an alkaline reaction. The reddish oxide changes in 

 water, when hot, to a white hydrate, which after a time turns 

 red litmus paper blue." 



Berzelius found the oxide of lantanium in the oxide of 

 cerium which I had separated from monazite, and sent to him 

 for further examination. It occurs with oxide of cerium, 

 alumina, lime, tin, manganese, phosphoric acid, &c. 



I have also lately found that it is contained in \\\e gadolinite 

 of Ytterby. 



Stockholm, May 3, 1839. C. Kersten. 



XLII. On a small Voltaic Battery of great energy ; some Ob- 

 servations on Voltaic Combinations and forms of Arrange- 

 ment ; and on the Inactivity of a Cojyper positive Electrode in 

 Nitro- Sulphuric Acid. By W. R. Grove, Esq., M.A., 

 M.R.L 



To R. Phillips, Esq., F.R.S. ^c. 

 My dear Sir, Wandsworth, Sept. 14, 1839. 



tTAVING been requested by many to republish the paper 

 -'--^ which I read to the Chemical Section at Birmingham, 

 and which has appeared with some inaccuracies in several pe- 

 riodicals, perhaps you will be kind enough to forward the 

 following for publication in the Philosophical Magazine. I 

 remain, my dear Sir, yours faithfully. 



W. R. Grove. 



A few days after my paper of the 15th April* was read to 

 the French Academy, I was applied to for directions as to 

 the construction of some batteries on the principle there in- 

 dicated, and I then suggested some changes of arrangement 

 which I considered advantageous : the apparatus were, how- 

 ever, not completed by the time I left Paris, and I have not 

 since learned how they have succeeded. That which I took 

 with me to Birmingham was hastily constructed, and is ca- 

 pable of much improvement; I will therefore briefly recapi- 

 tulate its effects, and proceed to describe what appears to 

 me the most convenient method of constructing similar bat- 

 teries for the usual purposes of experiment. As my trials 

 had been made with a decomposing apparatus much too small, 



* Vide Phil. Mag. for May. 



