Notes . 
478 
struggle with their fins against the influence of their swim- 
bladder. This organ renders them instable, both as to level and 
position. This, the author considers, helps to render them agile, 
as the most adtive of terrestrial animals are those which have 
the least stability. 
G. D. Liveing, F.R.S., and J. Dewar, F.R.S., communicate 
to the Royal Society a memoir on the history of the carbon 
spectrum, in reply to Mr. Lockyer’s paper on the same subjedt, 
read before the Society April 29th, 1880. In a subsequent paper, 
on the speftra of the compounds of carbon with hydrogen and 
nitrogen, the same authors remark— “ As we have now demon- 
strated the utterly unsatisfaaory charaaer of the crucial expe- 
riment on the strength of which Mr. Lockyer condemns in so 
sweeping a manner our conclusions, it follows that the whole 
fabric of his argument is utterly futile, and it seems unnecessary 
to add any further comments. 
J. B. Ramsay, F.R.S.E., has forwarded to the Royal Society 
a paper on the solubility of solids in gases. He concludes that 
a gas must have a certain density before it will aa as a solvent, 
and when its volume is increased to more than twice its liquid 
volume its solvent aaion is almost destroyed. The volume re- 
maining the same, the solvent power rises with the temperature. 
R. C. Rowe, F.I.C, Cambridge, has communicated to the 
Royal Society a simplification of Abel’s theorem. 
Mr. W. Crookes, F.R.S., has communicated to the Royal 
Society, in the form of a letter to the Secretary, Prof. Stokes, a 
condensed summary of the evidence in proof of the existence of 
a fourth state of matter. In conclusion he says, “ That which 
we call matter is nothing more than the effeft upon our senses 
of the movements of molecules. The space covered by the 
motion of molecules has no more right to be called matter than 
the air traversed by a rifle bullet has to be called lead. From 
this point of view, then, matter is but a mode of motion ; at the 
absolute zero of temperature the inter-molecular movement 
would stop, and, although something retaining the properties of 
inertia and weight would remain, matter , as we know it, would 
cease to exist.” 
According to Mr. A. Wilcocks, the shadows thrown by the 
planet Venus are distinguished from those thrown by the sun 
and the moon by their sharpness, the penumbra being totally 
wanting. This is due to the fa< 5 t that to our eyes Venus is 
merely a luminous point, whilst the light of the sun and of the 
moon emanates from broad disks. — Proc . Amer. Phil, Soc, f xvii., 
p. 705. 
