660 Proceedings of the Cambridge Philosophical Society, 
Remarhs on the Temperature qf the Egg^ connected with 
Physiology^ by John Murray, F. A. S., F. L. S. 
Observations and Experiments on the Temperature developed 
in Voltaic action and its unequal distribution^ by the same. 
Nov, 24.— -Mr Whewell read a paper, in which he deduced a 
formula for the angle between two planes^ whose equations are 
given, when the three coordinates to which they are referred make 
any angles whatever: To this was annexed a corresponding in- 
vestigation by Mr Lubbock of the angle contained between any 
two lines referred to coordinates of the same description. 
A paper by Dr Gregory was read, containing an account of 
some experiments, made in order to determine the velocity with 
which sound is tramsmitted through the atmosphere. Some of the 
results of these experiments are the following. That wind great- 
ly affects sound in point of intensity^ and that it affects it also 
in point of velocity ;■ — that when the direction of the wind con- 
curs with that of the sound, the sum of their separate velocities 
gives the apparent velocity of sound ; when the direction of the 
wind opposes that of the sound, the difference of the separate ve- 
locities must be taken that in the case of echoes, the velocity 
of the reflected sound is the same as that of the direct sound, 
that, therefore, distances may frequently be measured by means 
of echoes ; — that an augmentation of temperature occasions an 
augmentation of the velocity of sound, and vice versa. 
Dr Gregory mentions in a postscript, that it appears from 
experiments made by Mr Goldingham at Madras, (See this vo- 
lume, pp. 182--183.), that the velocity of sound is different indif- 
ferent climates ; and that hygrometric changes are not without 
their influence. 
Dec* 8. — Mr Peacock concluded his paper on the Newtonian 
discoveries, and read to the Society three unedited letters of Sir 
Isaac Newton to Dr Keith, preserved in the Library of Trinity 
College, Cambridge. 
Professor Cumming exhibited to the Society some experi- 
ments connected with the inflammation of hydrogen gas, when 
pjropelled upon platinum. 
