RN ES ES MR ce ein oe eer on PP ERI Kar Vet AUR Le) RRC 2 
a REPORT OF SCHIMMEL & Co. “Avra/OcroseR 1920. 
soluble, and insoluble substances, by means of the alkali salts of choleic a d 
bile acid. 3 
Semmler’s”) account (quoted by the author) a the iSutadoe of a stable’ compo 
between camphor and salicylic acid, is hardly a case of hydrotrophy, since there i: 
no aqueous solution; it forms, however, an addition to the explanatory addition- reactions : 
collected by von Rechenberg in his book: Theorie der Gewinnung und eae der 4 
dtherischen Ole durch Destillation, p. 627ff. ic 
The action of aqueous sodium salicylate in increasing solubility was first elated: 
out by Conrady’). Later, Duyk*), by shaking a sodium salicylate solution with a 
terpene, obtained a crystalline compound, which by solution in water or by long ~ 
heating at 100°C. could be broken up again. In three further papers he described5) 
(a) the general properties of aqueous salicylate solutions in raising solubilites (b) the ~ 
connection between the magnitude of the increase of solubility of numerous essential 
oils and their constitution, and (c) the use of the regularities thus found, in the — 
separation of several ethereal oils. Wolf®) employed aqueous solutions of sodium ~ 
and ammonium salicylate to dissolve freshly precipitated iron, aluminium, and copper iy 
hydroxide, Spaeth‘) a 5 per cent. sodium salicylate solution for the extraction of dyestuffs. ~~ 
The most extensive and general data come, however, from C. Neuberg®’), An ~ 
abstract of his researches is out of the question, but as an example of his methods 
and the type of phenomena investigated, we give the hydrotropic reactions of a nen 
40 per cent. aqueous solution of sodium benzoate. 
Hydrotropic reactions of an aqueous sodium benzoate solution (200 g. sodvum benzoate re 
made up to 500 ce.) ; 
1. 2.0 cc. pure amyl alcohol were dissolved by 1.0 cc. of the benzoate solution. - 
The mixture tolerated the addition of 0.5 cc. H.O; 1.0 cc. H.O caused the separation © a 
of an oily layer of the alcohol. ‘ 
' 2, 1.0 cc. sec. octyl alcohol gave an opalescent Satine with 1.2 ce, benzoate 
solution. 0.2 cc. HsO caused cloudiness. 7 
3. 1.0 cc. freshly distilled ethyl acetate were dissolved in 4.0 cc. benzoate solution by 2 
shaking. 2.0 cc. H,O caused slight turbidity, 5.0 cc. HO however gave a clear solution. ~ 
4. 1.0 cc. paraldehyde was almost dissolved by 7.0 cc. benzoate solution. 2.0cc. 4 
H,O produced a crystal-clear solution which could be) diluted with more water at will. — 
5. 1.0 cc. heptane dissolved in 10.0 cc. benzoate solution to a green-blue iridescent —© 
liquid; 1.0 cc. H,O caused a heavy discharge of oil. — 3 om 
6. 2.0 cc. citronellol were dissolved in 2.0 cc. benzoate. 0.2 cc. H:O ca 
cloudiness. ‘a 
7. 1.0 cc. geraniol was dissolved by 4.0 cc. benzoate solution. “02 cc. HO caused 
cloudiness, more H.,O caused discharge of oil. 
8. 0.5 cc. benzaldehyde dissolved on slight warming in 5.0 cc. benzoate solution. 
5.0 cc. H2O on warming caused separation of oily benzaldehyde. 
9. 0.5 cc. cinnamaldehyde were dissolved in 7.0 cc. benzoate solution. 
discharged oily aldehyde immediately—whether in cold or on heating—. 
1) W. 47586, KI. 120, dated 29, 2.1916. — *) Semmler, Die dtherischen Ole, vol. 3, p.511. — 4) Ph 
Ztg. 37 (1892), 180. Cf. Pharm. Zentralh. 33 (1892), 199; 40 (1899), 698; 43 (1902), 225. — +) Bull. Acad. 
Belgique 85 (1897), 15. As per Chem. Zentralbl. 1898, 1. 892. Cf. Pharm. Zentrath: 41 (1900), 126. ie = Ae 
Pharm. 1899, 348, 377 and 500. Cf. Report October 1899, 58. — *) Chem. Zig. Rep. 25 Cb); 20. 
Zentralh. 42 (1901), 792; 51 (1910), 615. — 8) Biochem. Zeitschr. 76 (1916), 107. 
