8 



Prof. W. N. Hartley and A. K. Huntington. 



Dilution 1,000, 2,000, 4,000, and 5,000 times yields a series of solu- 

 tions from which a remarkable curve may be traced, the lengthening 

 of the spectrum being very rapid between the two last points. 



Gedrat Hydrocarbon. (Dr. Gladstone.) Boiling-point 173° to 175°. — 

 Dilution to 1,000, 2,000, 5,000, and 10,000 times yielded a curve some- 

 what similar to, but less striking than, that derived from the photo- 

 graphs of oil of lavender. (Diagram 7.) 



Oil of Vitivert (Dr. Gladstone). — Two fractions of this substance 

 were distilled off the specimen, which was small in quantity. The 

 first part contained a little water, and the oil was yellow ; the second 

 portion was of a peculiar greenish tint, doubtless because of the 

 presence of some blue oil common to camomile and patchouli being 

 here in presence of a yellow oil. 



A brown resinous mass was left in the retort. The fraction photo- 

 graphed boiled between 280° and 285°. This is one of those sub- 

 stances which still absorb some of the more refrangible rays even 

 when diluted 30,000 times, while a dilution of 10,000 transmits no 

 rays beyond the line 18 Cd. (Diagram 7.) 



Oil of Turpentine. No. IV in Dr. Gladstone's paper, " Journal of the 

 Chemical Society," vol. xviii, p. 18. — This substance had become greatly 

 altered by keeping. Its original boiling-point was 160° C. It had 

 oxidised and no doubt become polymerised, since many fractions with 

 high boiling-points were distilled off. 



The following are the boiling-points of different portions of the 

 entire distillate : — 



150 — 160°, contained water. 



160—165°, 



165—180°, 



180—205°, 



205—228°, slightly turbid. 



228—310°, the greater portion boiled between 238° and 280°. 

 310—365°. 



At 320° the liquid was greenish in colour, and at 365° a yellowish- 

 green vapour was evolved. The oxidised products evidently split up 

 by the action of heat with the production of water and a hydrocarbon. 

 The fraction boiling between 228° and 310° was very much more 

 soluble in alcohol containing 30 per cent, of water than that with 

 a boiling-point of 160 — 165°. 



The fraction boiling between 228° and 310° did not transmit ray 

 12 Cd when diluted 1,000 times, and the spectrum was cut off at line 

 17 Cd, after diluting with 10,000 volumes of alcohol. 



The fraction boiling above 365° did not differ much from the pre- 

 ceding till a dilution with 10,000 volumes of alcohol was reached. 



