OF ARTS AND SCIENCES. 199 



Mr. Guyot also described the apparatus employed at the 

 Observatory at Toronto, by which the variation and the 

 minute oscillations of the magnetic needle are self-registered 

 photographically ; and exhibited several specimens of such 

 records. 



Mr. Paine briefly recapitulated some of the results of the 

 thermometrical observations he had carried on, in Boston and 

 its vicinity, during the last twenty-six years. 



He also moved the appointment of a new committee on the 

 Rumford Observations, of which the late Dr. Hale was for- 

 merly chairman, but from which there had been no report 

 since his death. 



Messrs. Tread well, Peirce, and Charles Jackson, Jr., were 

 constituted the committee. 



Dr. A. A. Hayes presented for examination, specimens of 

 Stereoptene, or the camphor derived from crude oil of vale- 

 rian, in the forms of solid, clear crystals and elongated porous 

 prisms. 



" This oil, which is manufactured by the society of Shakers, at 

 Enfield, New Hampshire, from the roots of the English valerian, 

 contains, with the volatile oil of the root, all the valerianic acid. It is 

 well known that the oil as usually obtained contains vaJerole, vale- 

 rianic acid, and borneole. By repose for several months, imper- 

 fectly guarded from the atmosphere, a crystalline aggregate withdraws 

 from the compound oil, in an impure state. These crystals are readily 

 purified by the usual processes. In the most regular form, they were 

 measured by J. E. Teschemacher, Esq., who refers them to the 

 rhombic system, — ' form, a right rhombic prism, with angles M on M' 

 121^^, and 58^-^, while M on e, the* terminal plane, is 134Sii.' Its 

 general form is that of thin elongated prisms ; cooled from a fluid, it 

 gives a crystalline mass ; sublimed, it forms snow-like flakes, or stella?. 

 The crystals have a high lustre, and a clear white color, with a slight, 

 but peculiar odor. Masses suddenly cooled have the specific gravity 

 1.030, and crystalline fragments float indifierently in sulphuric acid, 

 specific gravity 1.076, at 60° F. This substance melts at 198° F., 

 remains fluid at 195° F. ; its fusing-point, as determined, is between 

 196.7° and 197.2° F. 



