PROCEEDINaS OF THE POLYTECHNIC ASSOCIATION. 657 



liar odor belonging- to Russian leather, contains, among' other bodies, a 

 hydro-carbon resembling Cymole. Cedar wood and sandal wood oils are 

 composed almost wholly of a viscid oxidized compound having a high boil- 

 ing point. Cubebs, Calamus, Patchouli, Wormwood, Wild Camomile and 

 Millefoil were found to contain an intensely blue coloring 'matter, resisting 

 tlie action of most chemical agents, for which the name cerulean is pro- 

 posed. The pure hydro-carbons derived from the oils examined have not 

 generally powerful odors. -Those of about .846 specific gravity have the 

 lemony odor when freshly distilled and in their other characteristics resem- 

 ble camphene. The boiling points vary nearly as their density. Worm- 

 wood, tercbene, anise and mint have the lowest, being 160° C. Cubebs, 

 Calamus and Patchouli boil at 260'-'. The boiling point of Colophene, 315'^. 

 is by far the highest in the whole list. 



Adulteration of Food. 



The demand for chiccory, used in the adulteration of coffee, has been so 

 great as to lead to an imitation of it made from roasted carrot. This may 

 be called the adulteration of an adulteration. The chiccory dealers contend 

 that their article is more healthy than coffee, while the dealers in the escu- • 

 lent root point to its wholesome action on both man and quadrupeds as an 

 ai'gument in favor of their substitute. 



The best olive oil for the table is often adulterated with poppy, sesame 

 or ground nut oils. The olive oil used by manufacturers is often mixed 

 with colza oil, and the colza is in turn adulterated most frequently with ■ 

 whale oil. One of the best modes of discovering these admixtures, is to 

 treat the oil with nitric acid, saturated with hyponitric acid, which converts 

 the oleiue of most of the non-drying oils into a solid substance, while the 

 drying oils remain liquid. Geshardt states that one hundreth part of 

 poppy oil, in olive oil, will delay the solidification forty minutes; another 

 method is to treat the adulteration with caustic soda, or sulphuric acid, or 

 nitric acid, and. note the coloration. The test by density, proposed by M. 

 Lefebore, is not considered available, owing to the slight difference in the 

 specific gravity of a large number of the oils. 



The Use of Bromine in Photography. 



Tlie English journals are claiming for John F. Goddard, of London, the 

 credit of first using bromine in the daguerreotype pi'ocess. He may have 

 suggested its use, as others did, at an early day, but all attempts to use it 

 were unsuccessful, until Dr. Saul Beck Goddard, of Philadelphia, in 1840, 

 devised the {)lan of exposing the iodized mercury plate to the fumes of 

 bromine, and again to the fumes of iodine. This plan was kept secret for 

 two years, when it was revealed to certain parties in New York, and soon 

 became public property. It is well established that the first portraits by 

 Daguerre's process, were taken in America. Walcott expedited the pro- 

 cess by his reflecting camera, which he took to Europe in 1840, but several 

 minutes were required from the sitter, until the introduction of bromine, 

 when the process became almost instantaneous. 



