Herschel (4) defined oiliness as "the property that causes a difference in the friction when two lubricants of the same viscosity a t the temperature of the film are used under identical conditions." If one adheres rigorously to this definition, it seems that no account can be taken of the change of viscosity with pressure but only of its change with temperature. If, however, oiliness be defined as "the property that causes a difference in the friction when two lubricants of the same viscosity a t the temperature and pressure of the film are used under identical conditions," oiliness is made independent of viscosity and can be considered as a property of the system consisting of the lubricant and the rubbing surfaces. It must be remembered that, although no dimensions can be given for oiliness, it involves the physical state of the rubbing surfaces, and therefore the assignment of different values of oiliness to a number of oils would apply rigorously only for the machine with which the measurements were made. 0. C. Bridgeman, in December, 1933, before the Society of Rheology, said that oiliness was "that characteristic of liquids, which results in lowering of friction between surfaces moving relative to one another and which cannot be accounted for on the basis of viscosity." We would probably have a still better definition of oiliness if the word "viscosity" were replaced by "known properties of these liquids." The need for a word without inherent meaning such as "oiliness" has then disappeared in a measure as our knowledge of liquids increases.The fact that aP determines the temperature rise for all the oils studied in this investigation illustrates the meaning of the proposed definition of oiliness, for differences in friction that might be ascribed to oiliness can be accounted for by taking into account the variation of viscosity with pressure. It should also be pointed out here that the hydrodynamic nature of the lubrication is confirmed by the fact that the observed temperature rise is a function of viscosity only.*41though it appears that the variation of the viscosity over the bearing surface cannot be obtained, it is evident that, especially a t the higher loadings, the three oils will differ greatly. Similarly the value of G cannot be known, but it will evidently be greatest for the oil having the greatest value of a. This oil, having the greatest viscosity a t a given load, will then have the greatest hydrodynamic coefficient of friction but it should also have the thickest lubricant film. The fact that these thicker films would occur with oils showing the greater changes of viscosity with both pressure and temperature gives rise to interesting speculations on modern trends in lubricating oil refining. Further support to this theory of oiliness is given by the work of Needs (7) who studied the effect of change of viscosity with pressure in lubrication. He showed that in his experiments also effects that might be thought due to oiliness were, in reality, due to the increase of viscosity with pressure.F...

Surface Area of Oxide Coated Cathodes by Gas Adsorption 113 refluxing the substance melting at 141.5°contained 0.276% solids, while that of the substance melting at 161.5°contained 0.115% total solids. Two hundred mg. of the substance melting at 141.5°dissolved completely in 15 cc. of 7V/60 hydrochloric acid solution. In contrast 180 mg. of the substance melting at 161.5°did not dissolve in the same solvent after prolonged stirring. Warming at 56 °for thirty minutes caused the solution of the latter mixture, but neutralization with sodium bicarbonate and cooling caused it to flocculate. Sodium bicarbonate did not show this effect on the solution of the substance melting at 141.5°. Summary p-Hydroxylaminobenzenesulfonamide melting sharply at 141.5°and a related substance melting sharply at 161.5°have been studied.The higher melting substance is a crystalline trimolecular complex composed of two molecules of ^-hydroxylaminobenzenesulfonamide and one molecule of p-aminobenzenesulfonamide. This has been shown by chemical analyses, oxidation and quantitative determination of sulfanilamide in the presence of p-hydroxylaminobenzenesulfonamide.Philadelphia, Pa.

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