Mathematical and Physical Science. 325 



suppose to parallax and declension, and even cause other deviations 

 from Bernouilli's theory ? — Mr Lubbock replied, that unquestion- 

 ably it might so happen ; but, in his opinion, the discussion of a few 

 observations, like those made at Bristol, could not be expected to 

 point out very exactly the origin'or epoch of either of the variations 

 of parallax or declination, with sufficient exactness, to furnish secure 

 data for determining that they did not correspond to any one common 

 previous transit of the Moon. — Professor Whewell exhibited some 

 diagrams, which tended to illustrate his view of the question ; and, 

 in particular, he drew the attention of the Section to the circum- 

 stance, that the diurnal inequality, which was now beginning to be 

 observed, decided the question, inasmuch as its epoch could not by 

 any means be attributed to the same previous transit of the Moon 

 to which the others were referred — Mr Frend congratulated the 

 meeting upon the prospect now held out of determining precisely 

 that most important practical question, the true level of the sea. 



Mr Lubbock next made a communication respecting the forma- 

 tion of an empirical lunar theory. 



Professor Sir William Hamilton read his report on Mr George 

 B. Jerrard's mathematical researches, connected with the general 

 solution of algebraic equations. 



Professor Phillips read his Report of the Experiments insti- 

 tuted with a view to determine the Temperature of the interior of 

 the Earth. 



Professor Forbes gave an account of the experiments he had 

 directed to be made on subterranean temperature at the Lead Hills 

 in Scotland. 



The Rev. Mr Craig read a paper on Polarized Light. 



Section B — Chemistry and Mineralogy. 



President — Rev. Professor Gumming. 



Vice Presidents — Dr Dalton, Dr Henry. 



Secretaries — Dr Apjohn, Dr C. Henry, W. Herapath, Esq. 



Mr Watson read a paper on the Phosphate and Pyrophosphate 

 of Soda. 



Mr Ettrick noticed a new form of Blowpipe, by which the blast 

 of the common blowpipe was made as equable as that produced by 

 water-pressure. 



Mr Herapath then drew the attention of the section to the com- 



