344 General Notes. [April, 



system, but he does not think that, even after it has received all 

 its tributaries, the Kassai can be in any way compared with the 

 Lualaba. Where he passed it the last time, in 8° S. lat. in the 

 dry season, the Kassai had only a breadth of 394 feet, and a 

 depth of ten feet, with a current of rather less than two miles. 



Notes. — A relief map of the equatorial region of Africa on the 

 horizontal scale of one inch to twenty-five miles, and the vertical 

 scale of one inch to five thousand feet has recently been ex- 

 hibited in London. The French Government has undertaken 



to make a railroad between the Upper Senegal and the Niger 

 rivers. The surveying expeditions reached the starting point of 

 the road on the Senegal at Khay, seven or eight miles below Me- 

 dina on November 6th last. Commander V. L. Cameron, 



sailed from Liverpool on December 31, 1 881, for Axim to join 

 Capt. R. F. Burton in his exploration of the country at the back 



of the western portion of the Gold Coast colony. A Russian 



expedition for the exploration of Western Equatorial Africa is to 

 leave Europe in April. The Cameroons mountains are proposed 

 as the base of operations, and the exploration of the reported lake 



region to the east of them is the chief aim of the expedition. 



Dr. Josef Chavanne estimates the mean altitude of the continent of 

 Africa to be 2169.93 feet or double the mean altitude of the con- 

 tinent of Europe, which is estimated at 971.41 feet. Since the 



return of the three native envoys from England, King Mtesa 

 has been much better disposed to the English missionaries in 



MICROSCOPY. 1 

 American Societv'of Microscopists. — The Proceedings of the 

 fourth annual meeting of this Society, held at Columbus, Ohio, 

 August 9th to nth, 1 88 1, have been issued in a pamphlet of 102 

 pages and seven plates. Perhaps the most generally interesting 

 of the ten papers published, is ' " A Study of Blood," by Les- 

 ter Curtis, M.D., of Chicago. This paper describes a very careful 

 study, with one-tenth and one-sixteenth objectives, of fine defini- 

 tion and high resolving power, of pus corpuscles, and of white 

 corpuscles, and bleached red corpuscles of human blood, with a 

 view to determining the reality or otherwise, of the net work of 

 fine fibers described as occurring in such structures, by Dr. Carl 

 Heitzmann, of New York, in 1873, and subsequently by Dr. Louis 

 Elsberg, of the same city, Dr. Klein, of London, in his Atlas oi 

 Histology, and other writers. Although Dr. Curtis easily recog- 

 nized (what, indeed, it is not difficult to see) a more or less dis- 

 tinct appearance resembling a net-work, when the field was some- 

 what blurred and the outlines of objects indistinct, he uniformly 

 by such change of adjustment as would secure a fine definition 

 and distinct outlines, found the appearance of net-work replaced 

 1 This department is edited by Dr. R. H. Ward, Troy, X. Y. 



