REPORT OF THE SECRETARY. 53 



2. Chemistry of the Earth's Crust. 



3. Life in its Geological Relations. 



4. Geology of the Metals. Mineral Springs, Metamorphism. 



5. Igneous Rocks, Volcanoes, Mountain Chains. 



The interest is still kept up in the lectures, although they occasion- 

 ally called forth criticisms on account of the character of particular 

 courses, which, while they are received with much interest by one 

 class of hearers, are not in accordance with the taste of those whose 

 pursuits or reading lie in an opposite direction. 



While a large number of persons regularly attend the lectures for 

 the sake of the advantage to be derived from them, others, and par- 

 ticularly young persons, attend as a mere pastime, or assemble in the 

 lecture room as a convenient place of resort, and by their whispering 

 annoy those who sit near them. Frequent complaints have been 

 made on this account, and it has been suggested that it might be 

 well to try, as an experiment, a plan similar to that adopted at the 

 Lowell Institute, in which, as in the case of the Smithsonian Institu- 

 tion, free lectures are given to a promiscuous audience. To secure 

 proper order, and to prevent the interruption of the speaker by per- 

 sons arriving after the lecturer has commenced, a series of numbered 

 tickets may be distributed at the commencement of the season, and 

 the names of the persons who receive them entered in a book, oppo- 

 site the number of the ticket; and in addition to this, the doors may 

 be closed a few minutes after the lecture commences. 



Respectfully submitted. 



JOSEPH HENRY, 



Secretary. 



January, 1860. 



