NAPHTHA, BONE 



389 



of caustic potash, which will remove the nitrous vapours which are the cause of the 

 green colour. The purified hydrocarbon is then to be separated by a tap-funnel from 

 the water, and dried by digestion with sticks of caustic potash. If it be desired to 

 obtain the radical in a state of absolute purity, it must be distilled three or four times 

 over metallic sodium. 



The indifferent hydrocarbons obtained by the above process are colourless mobile 

 fluids, having an odour somewhat resembling the flowers of the white thorn. They 

 are very volatile, even at low temperatures, and have an average density of about 

 0716. When (he fractions with proper boiling-points have been selected, it will be 

 found that they correspond in specific gravity, percentage composition, and vapour- 

 density with the radicals of the alcohols, as will appear by the following Table, where 

 the experimental results obtained by the author of this article in his examination of 

 Boghead-naphtha are compared with the numbers found by other observers with the 

 radicals obtained by treatment of the hydriodic ethers by sodium, and also by the elec- 

 trolysis of the fatty acids. 



Comparative Table of the Physical Properties of the Alcohol Radicals, as obtained from 

 Boghead-Naphtha, with those procured from other sources. 



It has been said that the above hydrocarbons distilled away from the bromine- 

 compound in company with others which were removed by treatment with nitric acid. 

 It was subsequently found that the products formed by the action of the acid were 

 nitro-compounds belonging to the benzole series. The bromine compound contains 

 the C n H n series of hydrocarbons, the individual members being determined by the 

 boiling-point of the fraction selected for experiment. If we select that portion 

 boiling steadily between 160 and 170, we shall have a bromine-compound of the 

 formula C 12 H'-Br 2 ; but if the boiling-point of the naphtha lies between 180 and 190 

 the bromine-compound will be C 14 H 14 Br 3 . It is exceedingly remarkable that if 

 either _of these substances be treated alternately with alcoholic potash and sodium, 

 the original hydrocarbon is regenerated. By the mode of operating indicated above, 

 it is possible, therefore, to obtain two out of the three series of hydrocarbons in a pure 

 state. The third, namely, the benzole series, must be recognised by obtaining products 

 of decomposition. 



The acids and bases accompanying the hydrocarbons in Boghead-naphtha have not 

 been fully investigated ; it has, however, been ascertained that certain members of 

 the phenole series of acids and pyridine class of bases are always present. The 

 quantities present in the naphtha of commerce are small in consequence of the purifi- 

 cation of the fluid by the agency of oil of vitriol, followed by a treatment with caustic 

 soda.-C. G. W. 



NAPHTHA, BONE. Syn. Bone Oil ; Dippel's Animal Oil. This fluid is procured 

 in large quantities during the operation of distilling bones for the preparation of 

 animal charcoal. The hydrocarbons of bone oil have not as yet been examined, but 

 it has been found that the benzole series are present, accompanied by large quantities 

 of basic oils. The acid portions are also uninvestigated. The bases have been very 

 fully studied by Dr. Anderson, wb/> discovered in bone oil the presence of no less 

 than ten bases, several of them being quite new. 



The odour of bone oil is exceedingly offensive and difficult of removal. It does not 

 arise entirely from the presence of the powerfully-smelling bases', for even after 

 repeated treatment with concentrated acids it retains its repulsiveness. This is partly 



