P. T. Austen — Dinitroparadibrombenzols. 



Art. IK.— Photographs of the Spectra of Venus und a Lyra. 

 Note by Prof. Henry Draper, M.D.* 



Since the spring of 1872 I have been making photographs of 

 the sneetnl of the stars, planets and Moon, and particularly, 

 among the stars, of a Lyra and a Aquilse with my 28-inch 

 reflector and 12-inch refractor. In the photograph of a Lyra-, 

 hands or hroad lines are visible in the violet and ultra-violet 

 reo-iou unlike anything in the solar spectrum. The research is 

 and consumes time, because long exposures are neces- 

 sary to impress the sensitive plate, and the atmosphere is rareiy 

 in the best condition. The image of a star or planet must be 

 kept motionless for from ten to twenty minutes, and hence the 

 driving clock of the telescope is severely taxed. 



During last summer I obtained good results, and in October 

 took photographs of the spectrum of Venus, which show a large 

 number of lines. I am now studying these pictures, and have 

 submitted them to the inspection of several of my scientific 

 friends, among others Professors Barker, Langley, Morton aud 

 Silliman. There seems to be in the case of Venus a *"**« 

 of the spectrum toward H and above that line, of the s 

 acter as that I have photographically observed to tak 

 the spectrum of the Sun near sunset 



New York, December, 1876. 



Art. X.— On Dinitroparadibrombenzols and their Derivatives ; 

 by Dr. Peter Townsend Austen. Second Paper. 

 Tue separation of the three isomeric dinitroparadibromben- 

 zols I have already described in a previous paper, f . 



The residue from the separation of the a- and ^-isomers 

 consisted, for the most part, of ^-dinitroparadibrombenzols, 

 which forms the chief product of the nitntion. Inese resi- 

 dues were collected and, after several crystallizations from car- 

 bon disulphide, were recrystallized from glacial ttc 

 After six crystallizations, 'the fusing point remained constant. 

 Betadinitroparadibrombenzol. 

 - betadinitroparadibrombenzol crystallizes from its solu- 

 carbon disuV V'^d and peculiarly 



-r. -^ :i„ „~i„wu in t.hpi usual solvents, 



tsily soluble 



rinted on the third p 



>r of the January nui 



ber, and is here reproduced without change.— Ei 

 t This Journal, voL xii, 118, 1876. 



