Mercury. Oxygen. +------------------+ black. red. Bergman[4] 100 + 4 + -- Lavoisier[5] -- + -- + 7.75 to 8 Chenevix[6] -- + 12 + 18.5 Taboada[7] -- + 5.2 + 11 Fourcroy & Thenard[8] -- + 4.16 + 8.21 Sefstrom[9] -- + 3.99 + 7.99 My results give -- + 4.2 + 8.4 [Footnote 4: Kirwan’s Mineralogy.] [Footnote 5: Annals of Philosophy, Vol. 3, p. 333.] [Footnote 6: Philos. Trans. 1802.] [Footnote 7: Jour. de Physique. 1805.] [Footnote 8: Mem. d’Arcueil, Vol. 2. p. 168. 1809.] [Footnote 9: Annals of Philosophy, Vol. 2. p. 48.] Though the relative weights of oxygen and mercury may be investigated as above, yet it is from the weight of mercury and the acids in the salts of mercury, some of which are of a very definite character, such as the muriate and the deutomuriate, that the relative weight of the atom of mercury is best investigated. From these I first deduced the weight of an atom of mercury to be 167 about 10 years ago, and subsequent experience has not induced me to change the number, though it probably may admit of some correction. If the atom of mercury be denoted by 167, that of the protoxide will be 174, and that of the deutoxide 181; which makes 100 mercury take 4.2 and 8.4 oxygen for the oxides respectively, as in the above table. 5. _Oxide of Palladium._ The discoverer of this metal, Dr. Wollaston, has given us its distinguishing chemical properties; but we are indebted to Berzelius and Vauquelin for the proportions of oxygen and sulphur which combine with the metal (Vid. Annal. de Chimie, 77 and 78.) Few chemists have had an opportunity of making experiments on this metal, owing to its great scarcity and the consequent high price of it (1 shilling per grain). It does not seem desireable that any but those skilled in the more delicate chemical manipulations should operate upon articles such as the present. Berzelius treated the muriate of palladium with mercury, which abstracted the oxygen and left an amalgam of palladium and mercury; from the quantity of mercury dissolved he calculates that 100 palladium combine with 14.2 oxygen. This conclusion was corroborated by the circumstance that 100 palladium were found to take 28 of sulphur, or double the quantity of oxygen, which frequently happens with the metals.