liquid, a distillate of bornylamine was obtained unmixed with bornylhydroxylamine. The specimen of bornylamine obtained in this way melted at 162°, and gave [a] +41.0° in a 2 per cent. solution in absolute alcohol, showing that the proportion of neobornylamine was very small compared with that formed on reducing camphoroxime with sodium and amyl alcohol; an estimation of nitrogen gave 9.24 per cent., C10H1N requiring 9·15 per cent.

On reducing bromonitrocamphane in dilute alcohol with aluminium amalgam, the chief product is camphoroxime.

CH14

CH2

1:1-Iodonitrocamphane, CH11<CI·ÑO2

An aqueous solution of the potassium derivative of pseudonitrocamphane was treated with iodine dissolved in aqueous potassium iodide; the colour of the halogen was immediately destroyed, and a pale yellow, flocculent precipitate rapidly formed and settled beneath the liquid, which was decanted as soon as the iodine solution no longer gave rise to a solid derivative. The product was thoroughly washed and dissolved in hot glacial acetic acid, which was then diluted with water; when cold, the precipitate was filtered and recrystallised from the minimum quantity of hot alcohol, which was cooled as quickly as possible and filtered without delay. On analysis:

0-1841 gave 0.2610 CO, and 0.0862 H2O. C=38.66; H=5.20. 0.3210 13.1 c.c. of nitrogen at 19° and 770 mm. N=4.75. 0.2124 0.1608 AgI. I=40·91.

16

C10H1802NI requires C=38.83; H=5·18; N=4·53; I = 41.10 per cent. Iodonitrocamphane crystallises from alcohol in pale yellow prisms which darken at about 170°, and melt at 179°, forming a deep brown liquid which rapidly undergoes further decomposition; it dissolves very readily in acetone, benzene, petroleum, or ethyl acetate, crystallising from the last named solvent in lustrous, transparent prisms. Although quite stable in the solid state, solutions in acetone and alcohol darken within a few hours, and on evaporating the solvent, a dark brown, viscous oil remains; the solution in benzene, however, may be evaporated on the water-bath without undergoing alteration.

A solution containing 0.2497 gram dissolved in 25 c.c. of absolute alcohol at 19° gave a 13′ in a 2 dcm. tube, whence [a] -10.8°. A solution of 0.5 gram in 25 c.c. of benzene at 20° gave a -36' in the same tube, corresponding to [a] - 15.0°.

Iodonitrocamphane gives Liebermann's reaction for nitroso-derivatives. It slowly becomes brown on exposure to light, and is more easily decomposed than the corresponding chloro- and bromo-derivatives; for instance, hot aqueous potassium iodide withdraws iodine from the substance, and hot caustic soda also eliminates the halogen.

VOL. LXXVII.

U

1-Hydroxylaminocamphane (B-Bornylhydroxylamine),

C8H14

CH2 2

CH⚫NH⚫OH'

20 grams of aluminium (Aluminiumgries) were covered with a solution of mercuric chloride in absolute alcohol prepared by diluting a saturated solution with 10 volumes of the solvent; when the action had proceeded vigorously for nearly a minute, the turbid liquid was decanted, and the amalgam washed with absolute alcohol. A solution containing 20 grams of nitrocamphane in alcohol was then poured on the amalgam, some water added, and the flask containing the material at once fitted with a reflux condenser. On warming the liquid very gently, a vigorous action took place, and was allowed to proceed during 5 minutes; at the end of this period, the contents of the flask were cooled, filtered, and treated with 20 grams of crystallised oxalic acid dissolved in the minimum quantity of hot water. Alcohol was then distilled off on the water-bath, and a current of steam passed through the liquid in order to remove non-basic bye-products; when cold, the solution was filtered and rendered faintly alkaline with caustic soda, which yielded a granular precipitate composed of the oxalates of bornylhydroxylamine and sodium. It was therefore collected, suspended in hot water, treated with excess of caustic soda, and subjected to steam distillation. The aqueous distillate, which reduced ammoniacal silver nitrate almost immediately in the cold, was then heated and employed to extract the solid portion; the filtered liquid, on cooling, deposited minute, silky needles melting at 142°. The solid distillate, however, after being crystallised three times from petroleum, formed transparent, oblong plates melting at 154°, and both forms reduced cold ammoniacal silver nitrate almost immediately. On analysis:

2

0.0937 gave 0.2433 CO2 and 0.0949 H2O. C-70-81; H=11.25. C10H19ON requires C=71.00; H=11·24 per cent.

Bornylhydroxylamine is readily soluble in hot water, and the cold solution reduces ferric chloride, ammoniacal silver nitrate, and Fehling's solution almost instantaneously; mercury acetamide is not altered by it until warmed to about 50°, when a grey precipitate of mercury is produced and gas evolved. It is volatile in steam, and the vapour has a very faint odour suggesting bornylamine.

A more detailed account of this substance will be given in a future communication.

ROYAL COLLEGE OF SCIENCE, London,

SOUTH KENSINGTON, S. W.

XXVI.-The Refractive and Magnetic Rotatory Powers of some Benzenoid Hydrocarbons. The Refractive Power of Mixtures. An improved Spectrometer Scale Reader.

By W. H. PERKIN, LL.D., Ph.D., F.R.S.

In a paper on "Magnetic Rotatory Power, especially of Aromatic Compounds," published in the Transactions of this Society, some comparisons were made between the refractive and magnetic rotatory powers of aromatic compounds (Trans., 1896, 69, 1152), but these properties were not very specially considered in relation to the benzenoid hydrocarbons, because it was thought that the numbers published up to that date for their refractive values were probably not sufficiently accurate, owing to the fact that many of the hydrocarbons had not been obtained in a pure condition. The subject, however, appeared to be worth investigation, especially on account of the irregularities found between the magnetic rotations of these substances in which methyl is substituted for hydrogen of the nucleus or the side chain, as it was of interest to see whether the refractive values were of a similar character. Having been fortunate enough to obtain specimens of many of these hydrocarbons of exceptional purity, their refractive powers were therefore determined under as nearly as possible the same conditions, using in each case the same instrument, hollow prism, &c. The magnetic rotations of the new specimens which had not already been measured were also determined. The hydrocarbons used in this inquiry were:

All those marked * were prepared from the well-crystallised salts of the sulphonic acids, and for these I am indebted to Dr. Moody, with the exception of toluene, isobutylbenzene, and cymene, which were prepared in my own laboratory. The benzene was obtained from benzoic acid, the p-xylene was purified by strongly pressing the crystals between calico for a considerable time, and the isopropylbenzene was prepared from cumic acid. The pseudocumene and

mesitylene, not having yet been made from their sulphonic acids, were purified only by careful fractional distillation, and are therefore not of such well known purity as the foregoing. The tetraethylbenzene was obtained from Schuchardt, and was carefully fractionated.

The re-determination of the magnetic rotation of ethylbenzene differs but very little from that obtained previously with the same specimen, whilst with the new specimens of propyl- and isobutyl-benzenes and of o-xylene rather larger differences were obtained, as will be seen by the following comparisons of the molecular rotations.

The rotation of the new specimen of isobutylbenzene is seen to give considerably higher numbers than those previously obtained. This was expected, and the rotation now clearly indicates the existence of the iso-group which the old one did not (ibid., 1082). The rotation of o-xylene is also a little higher than that previously given, showing a somewhat larger difference, due to position, when compared with p-xylene, namely, 0.639, instead of 0.535.

The rotation of tetraethylbenzene is interesting, because it shows that the four ethyl groups introduced into the nucleus give an average result which is nearly four times that found for this group in ethylbenzene, thus:

Of course, as mentioned above, this is an average result, because the displacements would not have quite the same inflence in all positions.

I. REFRACTIVE POWER OF BENZENOID HYDROCARBONS AND ITS COMPARISON WITH THEIR MAGNETIC ROTATORY POWER.

From the results obtained, the following relationships are found to exist between the molecular refraction of the hydrocarbons, in which there is only one displacement of hydrogen in the nucleus by a fatty group. The numbers are for the line H..

From this table, it is seen that the introduction of methyl into the nucleus gives for the change in composition by CH, a number considerably higher than that found for subsequent additions which are not in the nucleus, but in the side chain, and that these amounts gradually diminish for each addition, although in every case they are higher than the ordinary value for CH2 in the fatty series, namely, 7.6. It is also seen that the iso-group, when introduced into the open chain, gives a lower number by 0-105 than the normal group.

The following table shows the difference of refraction due to position in the xylenes :

The purity of the mesitylene and pseudocumene not being so well established as that of the xylenes, a comparison of their refractive values in relation to position, where the differences are so small, would not be useful.

As previously noticed, it is seen that o-xylene gives lower numbers than either the para- or meta-derivative. This is also the case with other compounds (ibid., 1159), but the differences are not large and will not practically interfere with the following considerations of the methyl displacements, which are in the nucleus only. The first table on p. 270 shows the change, or average change, of refraction in these cases for each alteration of composition by CH2.