Annual Meeting.] 340 [May 2, 



Sulphides, the binary compounds, and the ternary compounds. 



Notwithstanding these difficulties the facts all imply gradation. 

 It makes no difference to us whether gradation leads up or down 

 or mingles both of these tendencies; whatever direction the true 

 classification may eventually take is immaterial. The indications 

 of what is already known show that gradation of some sort must 

 be the marked characteristic, and this alone would enable us to 

 harmonize the whole provisionally with the other departments of 

 the Museum. 



Independently of this, however, we have found important sup- 

 port in an opinion with which all chemists and mineralogists 

 whom we have consulted, agree. Both the chemical and the 

 molecular constitution of the elements may be considered as less 

 complicated than that of the purely inorganic and probably deriv- 

 ative compounds, and these in turn simpler than the Hydro-car- 

 bons. Theoretically also we are safe in assuming that the latter, 

 which are the products of organic bodies, composed wholly of 

 their fossil remains, oils, gums, etc., more or less altered by the 

 physical and chemical conditions to which they have been sub- 

 jected, are of later origin in time than the strictly inorganic 

 compounds, and that these in turn are more recent, as a rule, than 

 the elements of which they are made up. 



These fundamental facts are quite sufficient for our present 

 purposes and enable us to demonstrate that the same principles 

 of classification apply in this department as in all others. We 

 are already in receipt of letters from eminent teachers and 

 others expressing their gratification at the results of our work in 

 this department, and some of them strongly urge the immediate 

 publication of a proper catalogue. 



While we congratulate the Society upon the successful arrange- 

 ment of the most difficult department with which we shall have 

 to deal, it is also incumbent upon us to remember our obligations 

 to our former President, Mr. T. T. Bouve, to whose constant 

 labors in years past the Society owes the preservation and good 

 condition of the collection, and a large proportion of the speci- 

 mens. Next to him comes Dr. C. T. Jackson, who while living 

 was identified with us and whose name appears upon many of the 

 tablets. We are also indebted to Mr. Thomas Gaffield for valua- 

 ble gifts this year and in former years. 



