6 1 8 General Notes. [J uly , 



rhombic octahedrons, with the edges cut off; at 90 they glisten 

 with the most beautiful play of colors, like the diamond ; at times 

 groups are formed which seem exactly like a set of diamond 

 jewelry. 



Protector for Objectives.— A very convenient and useful 

 contrivance for covering the front surface of an objective, and 

 thereby protecting it from injury from corrosive fluids or gases, 

 and also for enabling the objective to be plunged directly into 

 water so that different layers of the liquid may be rapidly ex- 

 amined for microscopic constituents, or sediments at the bottom 

 examined in situ, is made by T. H. McAllister, of 49 Nassau 

 et, New York. Fig. 1 

 external view of the 

 it, and Fig. 2 shows it in se 



as applied to an objectix _. 

 ; made of brass and closed at fe& 

 Sjgy the lower end with a thir 

 glass. It is applicable to ; 

 lg ' '' jective of sufficiently 



mounting and long working focus, and il 

 well with powers from a I V 2 inch to a low-angled Fig. 2. 



#th or ith. 



Living Objects for the Microscope. — Living specimens of 

 animals and plants are supplied, for microscopical study, by A. 

 D. Balen, of Plainfield, N. J. Single packages are sent by mail 

 for 30 cents, or contracts made for a weekly supply, throughout 

 the season, at a still lower rate. 



SCIENTIFIC NEWS. 



— At a meeting of the New England Historic Genealogical 

 Society, held April 5th, Dr. William Barrows read the follow- 

 ing memorial to Congress : 



"To the Honorable the Senate of the United States: -Your 

 petitioners, the members of the New England Historic Genea- 

 logical Society, would respectively represent that there are in the 

 Territories of New Mexico and Arizona twenty-six towns of the 

 Pueblo Indians, so called, in all containing about ten thousand 



nhabitants ; that the number of their towns was once very 





greater; that those remaining are the remnant of very anci 



North America whose origin and history 1 



known 

 l their decayed and decaying antiquities ; that many ■ : 

 nave been abandoned by the decay and extinction of then- inU W 

 tants ; that many of these relics have already perished, and so nuo 

 the study of American ethnology vastlymoredifricuit.-thatthe.iiio 

 tion of the origin of the Pueblos and the age of their decayed Cines, 

 and the use of some of their buildings, now magnificent rain , 



