Isotherms for adsorption of organic solutes are divided into four main classes, according to the nature of slope of the initial portion of the curve, and thereafter into sub-groups.The main classes are: (i) S Curves, indicative of vertical orientation of adsorbed molecules a t the surface. (ii) L Curves, the normal or " Langmuir " isotherms, usually indicative of molecules adsorbed flat on the surface, or, sometimes, of vertically oriented adsorbed ions with particularly strong intermolecular attraction. (iii) H Curves ( ' I high affinity ") (commencing a t a positive value on the " concentration in solid " axis) , often given by solutes adsorbed as ionic micelles, and by high-affinity ions exchanging with lowaffinity ions. (iv) C Curves (" constant partition "), linear curves, given by solutes which penetrate into the solid more readily than does the solvent.The sub-groups of these classes are arranged according to the shape of the parts of the curves farther from the origin, and the significance of plateaux and changes of slope are described. Thus, if the adsorbed solute molecules in the monolayer are so oriented that the new surface they present to the solution has low attraction for more solute molecules, the curve has a long plateau ; if they are oriented so that the new surface has high attraction for more solute, the curve rises steadily and has no plateau.The choice of solutes for reliable measurement of specific surface areas is very restricted. It is suggested that p-nitrophenol may be one of the best compounds for this purpose.The significance of their features is discussed.* Part I, J., 1954, 4360; previous papers in this series were divided into two series, for inorganic and organic substrates respectively. Parts I-V, organic series, are considered as Parts VI-X in the present series. Thus, Part X is J . SOC. Dyers Colourists, 1958, 74, 846 (ref. 12a).

This case illustrates the successful use of clozapine in treatment-resistant childhood schizophrenia.

No abstract

The reactions of monolayers of model proteins (edestin and a wool derivative) on acid solutions of a number of 1:1-chromium-ligand dyes, of both monosulphonated and disulphonated types, and certain nonmetallized sulphonated dyes of similar structure, have been studied. Measurements of film area, pressure, compressibility, and viscosity have been made. All sulphonate groups appear to enter the water. Thus monosulphonated dye molecules penetrate between the protein chains, reducing the film viscosity, whereas disulphonates orient horizontally beneath the protein. A free —OH group present in the dye molecule causes it to bind more firmly to the protein, with increase in film viscosity and in surface compressional modulus (scm). All the dyes appear to act just as do the nonmetallized counterparts: film areas are increased; monosulphonates form mixed films and reduce both viscosity and scm of the film; disulphonates produce no change in viscosity or slope of the π/A curve but slightly increase the scm; the pressure-area changes are reversible. The viscosity of the protein film over a simple chromium salt solution alone, however, is very greatly increased. Evidence is obtained that reactions of the present protein films with dyes can reasonably be used to interpret dye-wool bonding reactions. There is no evidence from the present tests that the chromium atom in the dye molecule forms any bond with the protein. The good wash fastness which these dyes in wool have in technical practice must, therefore, be due solely to their high molecular weight and to mechanical effects of the structure of the fiber.

stearyl ketone, methyl stearyl ketone, etc. The second and third have almost identical molecular area and compressibility as films (cf. Table I), and their alkyl chains are nearly equal in length, but their polar groups differ in hydrogen-bonding properties. Thus they \ * r ' I tConcn. of tannic acid (mg.11.) .