A kinetic study of the acid-catalysed hydration of acraldehyde to /3-hydroxypropaldehyde (hydracraldehyde ; 3-hydroxypropan-l-al) in aqueous sulphuric acid confirms that the reaction is of the first order with respect to acraldehyde. The rate constants are independent of initial acraldehyde concentration, increase with increasing acid concentration, and are strictly proportional to Hammett's acidity function. /3-Hydroxypropaldehyde, isolated (in poor yield) from the hydration media and characterised as the 3 : 4-dinitrophenylhydrazone, dimerises spontaneously t o 4-hydroxy-2-2'-hydroxyethyl-l : 3-dioxan, the unsymmetrical structure of which is proved by acetylation and hydrolysis. Representative kinetic experiments on the dehydration of 8-hydroxypropaldehyde, using the dimer as starting material, demonstrate the ready reversibility of both the dimerisation of this aldehyde and the hydration of acraldehyde. A reversible mechanism proposed for the hydration of acraldehyde involves, as rate-determining step, the addition of a water molecule to the oxonium ion CH,:CH.CH:OH+ and the simultaneous redistribution of the charge t o give the oxonium ion TH,O*CH,CH:CH*OH which is the conjugate acid of the enol of /3-hydroxypropaldehyde. WITH the ready availability of acraldehyde on a commercial scale (see, inter alia, B.P. 569,625, 573,507, 600,454, 625,330; B.P. Appl. 22,712/39; Watson, C h e w Eng., 1947, 54, No. 12, 107), the preparation of P-hydroxypropaldehyde, an intermediate of great potential value in the solvent or the plasticiser field, has recently received considerable attention. Although P-hydroxypropaldehyde may be prepared in several ways (cf. Nef, Annalen, 1904, 335, 219; Glattfield and Sander, J . Amer. Chew. SOC., 1921, 43, 2675; Wohl and Schweitzer, Ber., 1908, 41, 3603 ; Stepanow and Schtschukin, Chem. Zepztr., 1927, I, 1167), most of the recent work has been concerned with the acid-catalysed hydration of acraldehyde (U.S.P. 2,434,110 ; German microfilmed reports P B 70,309, Frames 8214-8220 ; 73,508, Frames 7528-7537 ; and 19,417; G.P. Appl. D 89,752 IVd, Class 0, 1943).For the catalytic hydration processes described in the literature, conditions seem to be chosen rather arbitrarily and little systematic work appears to have been published in this connection.The kinetic data on the hydration of acraldehyde (Pressman and Lucas, J . Amer. Chew. SOL, 1942, 64, 1953, which are rather incomplete, are based on experiments with perchloric acid as catalyst and very dilute (about O ' O~M . ) solutions of acraldehyde, and are not, therefore, directly applicable to preparative work, A detailed kinetic study of the acid-catalysed hydration of acraldehyde was undertaken to provide fuller data, capable of such application, and an insight into the mechanism of the reaction, which has not hitherto been fully elucidated (cf. Hammett,

No abstract

The liquid-phase chlorination of n-hexane, n-octane, 1-, 2-, and 3-chlorohexane, and l-chloro-octane, using elemental chlorine, has been studied a t 20". Product yields of the mono and higher chlorides, together with unreacted n-hexane, have been compared with a statistical rrAodel for the chlorination of alkanes. The overall reactivities of the individual reactants have been measured, relative to n-hexane, and are in the order: n-octane > n-hexane = l-chloro-octane > l-chlorohexane > 2-chlorohexane > 3-chlorohexane. Yields of the monochlorides from the n-alkanes and dichlorides from the monochloroalkanes, respectively, have been determined by means of gas-chromatographic analysis. Relative selectivities for the abstraction of hydrogen by atomic chlorine have been calculated. In addition, the yields of the diastereoisomeric forms of 2,3-, 2,4-, and 2,5-dichlorohexane derived from 2-chlorohexane have been measured, and the steric course of the chlorination reaction is discussed.T H E chlorination of aliphatic hydrocarbons and their derivatives has been the subject of several reviews1 Of the chloro-alkanes investigated, those containing less than five carbon atoms have been studied in greatest detail. The chlorination of some higher alkyl chlorides has been reported by Horner and Schlafer.2 We have extended these studies by investigating the liquid-phase chlorination, at 20°, of the chloro-alkanes 1-, 2-, and 3-chlorohexane and l-chloro-octane, and, in addition, the two alkanes n-hexane and n-octane. The purpose of our work was to compare the product yields for an n-alkane with those predicted from a statistical model, and to study the reactivities of the chloroalkanes, directive effects, and the steric course of the chlorination reaction. EXPERIMENTAL I.C.I. cylinder chlorine, containing, in the initial fraction, 5-10y0 (v/v) oxygen, was deoxygenated before use by " bleeding off " the initial 10% (by weight) of the cylinder contents.The two hydrocarbons were shown by gas-chromatographic analysis to contain less than 1% (w/w) of aromatic and aliphatic hydrocarbons as impurities, and were used without further purification.Eastman-grade l-chlorohexane and l-chloro-octane were obtained from Kodak Ltd.3-Chlorohexane was prepared by reaction of hexan-3-01 with thionyl chloride. These materials contained trace impurities in the form of isomers and homologues of the corresponding chloro-alkanes. Chlorination did not result in the formation of any anomalous products.Apparatus and Procedure.-The alkane was weighed into the reaction vessel, consisting of a Materials.-Chlorine.This procedure reduced the oxygen concentration to 15-50 p.p.m. AZkanes. n-Hexane and n-octane were supplied by L. Light & Co.

Summary The iodic acid‐ammonium‐carbonate‐nickel salt reaction has been adapted for the routine spectrophotometric determination of morphine; the method is sensitive down to about 0·005 per cent, of morphine in solution and 0·03 per cent, of morphine can be determined with an accuracy within ± 2 per cent. Of the bases occurring with morphine in nature only pseudo‐morphine interfered weakly and the method has been used for the rapid determination of morphine in opium and poppy capsule. The factors affecting the formation of the green complex are briefly discussed.

A Complex is a group of emotionally invested ideas that have unconscious activities. Contrary though it be to the popular and sentimental idea of an overriding mother love, it is common, especially in child psychiatry, to find a mother's lively hatred and even homicidal wishes towards her child. I consider that this should be called “The Medea Complex.”