Though hydrogen is the very lightest gas known, and though, when uncombined, it has never been condensed to either the liquid or the solid state, some of its properties have led to the conjecture that it is probably a metal. In combination with nitrogen, as ammonia, it forms an amalgam with mercury, as is the case with most of the metals. The following conclusions from some experiments of Heir Magnus, of Berlin, strengthen the opinion that hydrogen is a metal. His apparatus consists of a glass tube within which a thermometer is fixed, which can be observed from outside. The tube is filled with gas, more or less condensed, and the upper portion of the glass tube is maintained at the temperatnre of boiling water, while the ambient air is constantly at 60 Fah. Only the upper part of the tube is heated, in order to avoid, as much as possible, ascending currents. The state of the thermometer in the different gases is compared with that at which it stands in a vacuum. The following are the results obtained: 1st. The temperature of a thermometer placed in a space heated above, varies with the diffrant gases con. tained in tho space. 2d. It rises higher in hydrogen than in any other gas. 3d. It is much higher in hydrogen than in the vacuum, .and much more so if the gas be condensed. 4th. Hydrogen therefore conducts caloric like the metals. 5th. In the other gases the temperature rises less than in the vacuum, and it rises much less when the gases are denser. 6th. It does not follow that these gases have no conducting power, but only that it is so feeble that the diathermancy of the gas disguises and annuls it. 7th. The extraordinary conductibility of hydrogen is evident not only when this gas is freely mobile, but also when it is enclosed in the eider down, or in any other sufficiently porous substance. 8th. This property of hydrogen is a fresh proof of its analogy with the metals. 9th. Hydrogen conducts not only caloric but also electricity better than all other gaseous substances.