or as preferred by some: H-O-H, is not in conformity with established facts. Expressed as here shown, both hydrogen atoms are assigned equal values, when in fact only _one of the atoms is united to oxygen in form of hydroxyl_, while the second is loosely attached to the univalent hydroxyl group. Viewed in this light, water then is decomposed according to the equation: H_{2}O = H + (OH), never in this manner: H_{2}O = 2H + O. Hence, water must be considered as a combination of one hydrogen atom with one molecule of hydroxyl, expressed by the formula H(OH), and it is this atom of hydrogen _not_ united to oxygen which is eliminated in the generation of oxygen or substituted by metals and alkyl groups. The hydrogen in the hydroxyl group cannot be substituted, excepting it be the entire group as such; this is proved by the action of the halogens, in their phosphorus compounds, upon water, when the halogen takes the place of the hydroxyl group, but never that of the hydrogen. Now as to some logical deductions from the foregoing considerations. Hydrogen is by many looked upon as a true metal. This theory cannot be directly proved by the above, but it is certainly greatly strengthened thereby. To compare. Hydrogen is a powerful reducing agent; it is similarly affected by the halogens, the hydroxyl group, the acid radicals, oxygen and sulphur; hydrogen and members of the univalent alkali metals group are readily interchangeable; it forms superoxides analogous to the metals; its analogy to the alkali metals as exhibited in the following: H H(OH) HCl HNO_{3} H_{2}SO_{4} H_{2}S H_{2}O_{2} K K(OH) KCl KNO_{3} Na_{2}SO_{4} Na_{2}S K_{2}O But if we consider hydrogen as a gasiform metal, we naturally arrive at the conclusion that _water is the hydroxide of this gasiform metal_, that is _hydrogen hydroxide_, while gaseous hydrochloric and hydrosulphuric acids would be looked upon as respectively the chloride and the sulphide of the metal hydrogen. This would then lead to curious conclusions concerning the hydroxyl group. This group would, by this theory, become an oxygenated metal radical similar to the hypothetical bismuthyl and uranyl, and yet one in which the metallic character has disappeared as completely as in the ferrocyanic group. An entirely new light is shed by this view upon the composition of hydrogen peroxide, which would be looked at as two free hydroxyl groups joined together thus: (OH)--(OH), analogous to our di-ethyl, diphenyl, dicyanogen, etc. Considered as dihydroxyl, it would explain the instability of this compound.