PROCEEDINGS OF THE SOCIETY. 
119 
that a very hearty vote of thanks be given to the President for his 
address, and that he be asked to allow it to be printed in the Journal. 
Mr. Gifford said he had been engaged for some time in measuring 
the refractive indices of various substances, and Mr. Nelson had, in his 
address, put before them a way in which the thing might be done very 
much more easily than had been possible before. The ordinary method 
was to take each measurement from three points in a circle, and if the 
spectrum contained a great number of lines, a great deal of time would 
be taken up and the process became very tedious, since five or six mea- 
surements had also to be taken at each point to get a proper average. 
Now, however, it was only necessary to measure two lines, after which 
Mr. Nelson’s formula was applied, and the thing was done. He should 
like to ask Mr. Nelson how far he had carried his experiments ? In the 
series of measurements put before them, only five or six lines had been 
taken — the Jena table gave five, and Chance’s gave two or three only. 
These ranged from A in the spectrum to G, but the spectrum had been 
explored much farther into the red, and at the other end into the ultra- 
violet as far as 1852*2, the extreme line of aluminium discovered by 
Sir G. G. Stokes ; and he was very much interested to know how far 
this method would g ', and if Mr. Nelson had taken the wave-lengths 
below A or above G. He was sure they would all appreciate the 
amount of labour which Mr. Nelson had bestowed upon this subject. 
Mr. Karop said he should like to be allowed to second the motion 
of Mr. Michael that the thanks of the Society be given to the President 
for his very able address, and that he would allow it to be printed and 
published in the Journal of the Society in the usual way. 
Mr. Michael then put the motion to the Meeting, when it was unani- 
mously carried by acclamation. 
The President said he could only thank Mr. Michael for proposing, 
Mr. Karop for seconding, and the Fellows of the Society for the very 
kind way in which they had given him such a cordial vote of thanks. 
Mr. J. J. Vezey thought the Fellows present would agree with him 
that the Annual Meeting afforded a very pleasant opportunity of ex- 
pressing the indebtedness of the Society to its Honorary Officers for 
the way in which their work had been carried on during the past year, 
and he had therefore very great pleasure in proposing that the best 
thanks of the Fellows be given to the Honorary Secretaries and the 
Treasurer. The Fellows of the Society had had some opportunity of 
seeing how well Dr. Hebb had carried out the duties of a Secretary at 
the Ordinary Meetings ; but only those who were upon the Council 
knew how great an amount of time and energy he had given to the 
work. Dr. Dallinger, they were pleased to know, had so far recovered 
his health as to be able to come amongst them more often during the 
past year. They were very glad indeed to see him at the meetings, and 
to have the benefit of his advice and help at the Council Meetings. 
AVitli regard to the Treasurer, the Report he had read that evening 
would speak for itself, but in addition to keeping the accounts in better 
order than they had been for years, he had, as mentioned in the Report, 
done very great service to the Society in preserving and remounting a 
large number of slides in the cabinet. He (Mr. Vezey) would like 
