1883. Ill Trans. N. Y. Ac. Set. 



vegetation from which the carbon in the shales was derived, and the 

 aggregations of gulf-weed in the " Sargasso Sea," etc. It was entirely 

 improbable that, however dense the vegetation might be upon the sur- 

 face of the ocean in such regions, any accumulation of carbonaceous 

 matter could lake place upon the oceanic bottom, from the exceed- 

 ingly slow rate at which mineral detritus can be there deposited to pro- 

 tect such organic matter from oxidation ; nor have any such accumula- 

 tions been found in the deep-sea dredgings of the Challenger or other 

 expeditions. 



Dr. Newberry doubted whether any dredgings had ever been made 

 beneath the Sargasso Sea, but he also disbelieved in the possibility of 

 such a carbonaceous deposit in the deep ocean. He had only desired,by 

 the allusion to the Sargasso Sea, to indicate the probability of a similar 

 aggregation of floating algas upon the surface of the shallow waters 

 beneath which these shales must have been formed. 



April 9, 1883. 



Section of Chemistry. 



The President, Dr. J. S. Newberry, in the Chair. 



Thirty-five persons present. 



The Corresponding Secretary called attention to the recent 

 death of Dr. Joseph Priestley, of Northumberland, Penn., the 

 last surviving descendant of the eminent chemist of that name, 

 and remarked on his genial kindness and eminent talent as a 

 physician, and the influence of his character and position, by which 

 he generously assisted in the success of the Centennial Celebration 

 of American Chemists at Northumberland, in the summer of 1874. 

 After discussion by Mr. Elliott and the President, it was 



Resolved, that the Corresponding Secretary be requested to con- 

 vey to the family of the deceased our sincere sympathy in their 

 bereavement, and our high appreciation of his character. 



Dr. Albert R. Leeds then read a paper, entitled: 



AN ACTINIC method FOR THE DETERMINATION OF ORGANIC 

 MATTER IN POTABLE WATER, 



with the application of the method to the water supplies of Philadel- 

 phia, Newark, Jersey City, Brooklyn, and New York. 



At the present time there is no method known of determining ac- 

 curately the amounts and kinds of organic matter existing in the water 

 we drink. The amounts are so small, the kinds so various, the in- 



