53 
be explained by the hypothecation of a stratum of some 
peculiar gas above the atmosphere. A gas of a ^'ferruginous 
nature'' is the expression of Dr. Dalton. Now hydrogen 
in the higher chemistry is not only classed among the 
metals, but Faraday and others have shown that in its rela- 
tion to magnetism it is nearly allied to iron, so that a 
stratum of hydrogen above the air would seem to exactly 
answer Dr. Dalton’s postulate. If it should exist, the earth 
would resemble the sun in one remarkable feature, for we 
now know that the sun is girdled with an immense layer of 
hydrogen. Lastly, he would add that the heterogeneous 
texture of the gaseous nebula, like the great nebula in Orion, 
seems to argue that the law of the equal diffusion of gases 
does not prevail there. 
Mr. Hov^'orth presented these facts with considerable 
hesitation, his excuse for doing so being his view that all 
physical laws are tentative only ; that is, they are good as 
long as they explain all the facts, and no longer, and that it 
sometimes becomes a duty to present apparently aberrant 
and abnormal facts to an audience so v/ell qualified to 
criticise them as the Manchester Literary and Philosophical 
Society, in order that they may either be brought within 
the law or that the law may be revised. 
Ordinary Meeting, December 15th, 1874. 
Edward Schunck, Ph.D., F.R.S., tc., President, *in the 
Chair. 
Mr. Joseph Garrick and Professor Morrison Watson, M.D., 
were elected ordinary members of the Society, 
Rev. Wm. Gaskell, M.A., read an interesting account of 
Horrocks’ and Crabtree’s Observations of the Transit of 
Venus in 1639, published in the Annual Register for 1769. 
