308 



efforts and studies of Mr. Way of Franklin, Delaware coun- 

 ty, in developing the palaeontology of these rocks. 



After Prof. Hall's paper and some general conversation 

 on these subjects, the Institute adjourned. 



February 17, 1863. 



The president, Mr. Pruyn, presided. 



The following donations were announced : 



Report of the British Association for the advancement 

 of Science, 1860. 



Proceedings of the American Academy of Arts and Sci- 

 ences. 



Historical Collections of the Essex Institute. 

 Proceedings of the American Philosophical Society. 



Dr. Howard Townsend read the paper for the evening, 

 on Spectral Analysis. 



He gave a history of the various discoveries in regard to 

 the solar spectrum from Newton to the present time, espe- 

 cially with reference to the lines crossing the spectrum. 

 These last had been studied more particularly by Kirchoff 

 and Bunsen, two German chemists. They had studied also 

 the spectra produced by the flames of different burning 

 substances. They had discovered a universal law in regard 

 to the lines crossing the spectrum, and the body being 

 burned. Each body when bound in flame produced in the 

 spectrum lines peculiar to itself ; so that it becomes easy to 

 detect the nature of a body by burning it in flame. They 

 detected two new metals not before suspected, by this 

 means. By a magnificent generalization, they concluded 

 that the lines in the solar spectrum were caused by the 

 presence in the atmosphere of the sun, of substances like 

 those whose flames produced the same lines on the earth. 

 The conclusion of these chemists was that the sun was 

 composed of matter identical in elements with the matter 

 of the earth. 



At the close of Dr. Townsend's paper, 



