We have improved the Frankel and Cornelius method for preparing /3-aminoethylsulfuric acid from monoethanolamine and sulfuric acid so that the theoretical yields may be obtained readily.2. The crude product is purified easily, since water is the only other reaction product.3. Although copiously soluble in water, the compound is not precipitated, even from its concentrated solutions, by acids, alkalies, or salts.4. In aqueous solution the compound exists in the simplest possible state of molecular aggregation.5. The compound displays many of the properties common to the aliphatic amino acids.6. The ester linkage of the compound is very resistant to hydrolysis, thus allowing it to be used in solution with substances that catalyze hydrolytic reactions.7. The compound is worthy of further study as an ampholyte.

No abstract

Tmis paper is a report upon a somewhat extensive investigation of the hydrogen electrode titration of crystalline egg albumin. The work was undertaken with the object of examining the limitations of the method as a means of establishing a quantitative definition of the amphoteric properties of a protein. Crystalline egg albumin was chosen because it is probably the best accredited example of a molecularly homogeneous protein. The extensive work of S0rensen and of his colleagues, of Svedberg and of others indicates that of the common protein preparations egg albumin exhibits the greatest degree of constancy in composition, molecular weight and solubility under varying conditions of preparation and treatment. This protein has the further advantage that it is soluble in water over the whole titratable range of PH.The data which will be considered derive from observations gathered over a period of five years upon five distinct preparations of the protein. These preparations had been submitted to considerable variations in treatment prior to titration. Each was crystallised four times-one by the original method of S0rensen [1917], the others by a modification of this method in which sodium sulphate replaced ammonium sulphate as the salting-out agent. Two of the latter preparations were employed in the electrometric work without having been reduced to the dry state. Two were converted into a dry powder and stored for some time before use. One of the dry preparations was dissolved in water and titrated without further purification, the other after one more recrystallisation. Some details of the method of preparing crystalline egg albumin in the dry state with the aid of sodium sulphate will be found in the experimental section.Each product was prepared for titration as a stock solution which had been dialysed in distilled water until the sulphate ion could not be detected in a dialysate after sixteen hours' contact with the solution. Varying amounts of dilute HCI or of NaOH were added to equal volumes of the stock solution and the mixtures were then diluted to a predetermined concentration of protein. The majority of the observations relate to systems containing 22-25 g. of protein in 1000 g. of water. In a few cases this value was reduced to 15 g. and in a few others raised to 45 g. The PE of each mixture was determined in a rocking hydrogen electrode [Clark, 1928] at 250, using a saturated calomel half-cell and a saturated potassium chloride liquid junction. The calomel half-cell was calibrated with the aid of 0.1 N HCI, for which we assumed a pH of 1-075 [Scatchard, 1925]. The interval between the preparation of a mixture and the determination of its PH did not exceed 1 hour.Commonwealth Fund Fellow. ( 227 )

Vol. 62 catalytic thermal decomposition of (a) ethylene for the hydrogenation of acetone at 110°, (b) methane for the hydrogenation of carbon dioxide at 315°, and of nitrous oxide at 73.5°2. The experimental evidence indicates that the surface of the nickel catalysts studied was non-uniform because (a) catalysts which no longer catalyzed the decomposition reactions were still active at lower temperatures in the hydrogenation reactions, (b) certain parts of the surface were more active than others in the hydrogenation of acetone, (c) heating in hydrogen a surface upon which the hydrogenation of nitrous oxide had occurred caused selective activation or poisoning according to conditions, (d) the nickel surface responsible for about two-thirds of the hydrogenation of carbon dioxide could be poisoned without affecting the nickel surface which catalyzed the hydrogenation of nitrous oxide. Providence, R. I.

This paper is devoted to a discussion of the contribution which electrode titrations may make to the quantitative definition of the amphoteric properties of a protein. The argument will be illustrated by experimental curves for the titration of egg albumin with HC1 and with NaOH under a variety of conditions. Some reference will also be made to a comparable study of p-lactoglobulin,l the detailed results of which will be published elsewhere.The curves, which will be discussed, represent the relation between p H and a quantity which we will designate h. This quantity is simply the difference between the equivalents of HC1 (f ve) or of NaOH (-ve) added to one mole of protein and the equivalents of free H+ (f ve) or of OH-(-ve) present a t the observed pH. We have adopted a value of 45,000 for the molecular weight of egg albumin.2The corrections for free H+ and OH-have been computed on the