9f6 Register of ike Weather in Plymouth. [Oct. 



XL 



Solubility of Rhodium in Adds. 



A gramme of rhodium in fine powder exposed to the action of 

 eight grammes of nitro-muriatic acid composed of equal parts of 

 its two constituents was not sensibly attacked, and the acid scarcely 

 became coloured. 



Seeing that this metal is not dissolved in nitro-muriatic acid of a 

 moderate concentration, I treated it anew with a very strong acid ; 

 but it was not dissolved any more than the first time. As the rho- 

 dium, when pure, is insoluble in all acids, both simple and com- 

 pound, we must suppose that in the ore of platinum it is alloyed 

 with other metals that favour its solution, when crude platina is 

 treated with nitro-muriatic acid. It has not been in my power, in, 

 consequence of this insolubility, to examine, the properties of the 

 simple salts of rhodium. * 



I shall give, in a second memoir, the method of separating osmium 

 and iridium from the foreign bodies which constitute the insoluble 

 residue in the ore of platinum ; and I shall likewise describe th« 

 properties of these metals as far as I have examined them. 



Article VIII. 



Register of the Weather in Plymouth for the first Six Months of 

 1814. By James Fox, jun. Esq. With a Plate. 



(To Dr. Thomson.) 



SIR, 

 AcREi:ABr>E to my promise,* I send you a copy of my meteoro- 

 logical journal for the first six months of the year )rSl4. You will 

 perceive that 1 have included January in it (though given in my 

 former communication) ; my reason fur so doing is, that if you 

 should deem it worthy the expense of an engraving, the table will 

 be more perfect with the addition of that month. It being my 

 intention to continue these observations for three years, six such 

 engravings would ma! e a pleasing map of the atmosphere of Ply- 

 mouth ; whereas if January be omitted, it will be rendered incom- 

 plete, f 



I am, &c. 



Jamks Fox, jun. 



* JnnaH of Philosophy, vol. iii. p. 274, April, 1814. 



+ Mr. Fox baa stated, in a private lcitcr, na-nni for COBgidering the enonnoca 

 /all of snow in January a-- measured by him to be correct; and I muft own they 

 appear to me satisfactory. — T. 



