NATUKAL PniLOSOPHY. 179 



sisted in lieating it in an atmosphere of compressed gas. This 

 sjjecimen was accompanied by a paper, in wliich it was explained 

 that the variations of densit}'", of conducting power, etc., produced 

 in the palhidium by the absorption of the hydrogen, seemed to 

 indicate that a true alloy had here been formed, and thus to es- 

 tablish the metallic character of the consolidated gas. Various 

 rumors of this circumstance have been circulating in our daily 

 papers, in which the specimen presented by Mr. Graham was ex- 

 alted into ** an ingot of hydrogen," and though, in comparison 

 with this, the actual f^ict may seem disappointing, yet in its true 

 relations it is sufficiently wonderful, and is certainly a decided 

 step towards the not impossible realization of the veritable "in- 

 got" at some future time. As a mere evidence of the intensity of 

 molecular force, this experiment of Graham reaches into the 

 marvellous and the incomprehensible. If the space occupied by 

 the condensed hydrogen had been entirely void of all other mat- 

 ter, the force required to reduce 800 volumes to one volume 

 would have been 800 atmo-^phores, or 12,000,000 pounds to the 

 square inch, but with a metal like palladium, as dense as lead, it 

 would be a large allow^anco to suppose that one-thousandth part 

 of its volume were void space, or consisted of the interstices be- 

 tween its particles. To compress the 800 volumes into this bulk 

 would then demand a force of twelve million j)ounds, or six thou- 

 sand tons per square inch. Yet this inconceivable force is quietly 

 exerted by the atoms of palladium in their attraction for those of 

 the hydrogen. This substance, hydrogen, has other evidence of 

 its metallic character besides these experiments of Graham. We 

 do not allude to its chemical and eh^ctrical connections with the 

 metals, but to an action closely related to this absorption by 

 palladium, which, though for some time known, presents a new 

 aspect when viewed in the light of this result. In 1863, Dr. 

 Charles M. Wetherill made a series of investigations on the Am- 

 nion iacal Amalgam, which very clearly demonstrated that the 

 peculiar compound known by that name was not an alloy of any 

 such compound as NIP with mercury, but was, in truth, a 

 " suds " of mercury, frothed up with minute bubbles of hydrogen 

 and ammonia, but yet holding the gas in such close union as 

 evidenced a decided affinity between the two bodies. We might 

 then justly consider this attraction for and retention of the hydro- 

 gen by the mercury as being analogous to the infinitely more 

 energetic action which is shown by palladium, and like it, also, as in- 

 dicating a tendency in the hydrogen to alloy itself in the manner 

 of a metal with other metallic elements. Remarkable as is this 

 element in its chemical relations, it is equally notable in another 

 respect, about which a few words may be appropriate (in connec- 

 tion with the late astronomical discoveries of which we have re- 

 cently spoken), under the head of The Cosmical Relations of 

 Hydrogen. — When Miller and Huggins attacked, with the spec- 

 troscope, the problem of the constitution of the nebulce, which 

 had successfully defied the most diligent telescopic research, and 

 had demonstrated that many of these were of gaseous consistency, 

 hydrogen was one of the substances first recognized in the won- 



