portion of matter, so minute that it cannot be further reduced, and it is 
perfectly legitimate to suppose that atoms have a spherical form : if, how- 
ever, as Newton has suggested, the spaces intervening are indefinitely large 
compared with the atoms themselves, it does not much matter what form 
they are supposed to have : but the phenomena of crystallization, which 
require the existence of unequal polar forces in two and sometimes three 
directions, seem to point rather to a spheroidal, or ellipsoidal form. After- 
wards Professor Challis speaks of their “ sensible magnitude.” 
Professor Challis. — I mean matter not infinitely divisible. 
The Chairman. — I supposed the phrase meant magnitude capable of 
appreciation by the senses, but that is not the case with regard to atoms of 
matter. Then Professor Challis has ascribed both gravitative attraction 
and, as 1 1 suppose, magnetic and electric attractions and repulsions, to 
currents of ether : it may be so, but as we know nothing of it, and cannot 
tell whether ether has currents or not, the whole of that part of the paper 
is to my mind imaginative, and is not capable of being in any degree re- 
duced to the test of sensation and experience. It is a theory, and must stand 
as such. In one place Professor Challis speaks of a moving force being 
personal force, but in many cases that is not so, a watch spring moves a 
watch, but that is not a personal force. 
Professor Challis. — It seems to mean the same. 
The Chairman. — I may remark, in conclusion, that there are many other 
points on which, if time permitted, I should be disposed to join issue with 
the author of the paper. 
Professor Challis. — Through defect of hearing I have not heard nearly 
so well as I wished to have heard the remarks which have been made upon 
my paper, and I therefore must hold myself excused if I pass over a good 
many things which I have not sufficiently heard. I will, however, make men- 
tion of a few, the purport of which I caught and can remember. Prebendary 
Row asked me whether I thought ether was composed of atoms. I say it 
is composed of atoms, because I do not know of any material substance that 
is not so composed, and I consider ether to be a material substance. With 
regard to my use of the Septuagint, I have stated in the paper the grounds 
on which I use it. I anticipated that there would be a discussion relative to 
the Hebrew text, but I had determined beforehand that that would be 
shifting the basis of my argument, and that I could not enter upon it. I 
only enter upon what I have undertaken, and that is to draw inferences from 
the Septuagint ; but I have not undertaken to compare them with the sense 
of the Hebrew text. The word iiri<p'tptro I referred to simply as respects 
one point, and that point was that the word is used in the first chapter of 
Genesis, just as it is used in that passage of Genesis which relates to the ark 
being borne up by the waters of the Deluge. Other applications of the 
word were not to the point I was concerned with. The identity of the use 
in the two passages was all that I had to consider, and it is remarkable that 
