leucylglycyl-leucine are converted into the anhydride when heated with glycerol. P. W. CLUTTERBUCK.

C.

Alcoholytic cleavage of proteins. I. GRÄNACHER (Helv. Chim. Acta, 1925, 8, 784-791).Keratin (from white goose-feathers), heated with absolute ethyl alcohol or methylated spirit under pressure at 170-175°, is dissolved more rapidly than by 1% hydrochloric acid at 180°. The residue on evaporation of the solution is a pulverisable solid containing 15% of nitrogen of which only 0.7% is amino-nitrogen. Extraction with water and ether yields diketopiperazine (m. p. 280-282°) and a syrup which may be distilled at 5 mm. pressure. The viscous water-soluble oil of b. 130-140°/5 mm. p. gives no amino-acid reactions until boiled with concentrated hydrochloric acid. Benzoylglycyl-leucineethylamide (this vol., 78) and benzoyldiglycylglycine are recovered unchanged after prolonged heating at 170-180° with ethyl alcohol, whilst glycine anhydride is obtained from diglycylglycine under similar conditions. This evidence is considered to point to some other structure in the proteins than the generally assumed polypeptide linking of amino-acids. G. M. BENNETT.

Muscle albumin (myoalbumin). M. PIETTRE (Compt. rend., 1925, 181, 737-739; cf. A., 1924, i, 228, 348).-Muscle extract is purified by saturation with ether, which precipitates 3.85% of bulky material, and is then treated with acetone, which precipitates 0.53% of globulin-like proteins. The mother-liquors

are saturated with ether and when kept in the cold deposit 2.1% of myoalbumin, coagulating at 45-47°, yielding a clot, [a]D-27° to -30° (for different species of animals), giving a limpid solution in water of high refractive index, not possessing marked anaphylactic properties. L. F. HEWITT.

Volumetric determination of nitrobenzene. I. M. KOLTHOFF (Chem. Weekblad, 1925, 22, 558).— The nitrobenzene, dissolved in a mixture of alcohol and water, is reduced in presence of sodium hydroxide by addition of titanous chloride; after oxidation in air of the excess of titanous hydroxide, bromate and bromide are added, and the whole is acidified; after 5 min., potassium iodide is added and the liberated S. I. LEVY. iodine titrated with thiosulphate.

Qualitative test to show the absence of citrate or tartrate in mixtures. J. B. PETERSON (Ind. Eng. Chem., 1925, 17, 1146).—A method is described for testing for the absence of citrates or tartrates in mixtures, based on the fact that the purple colour of the ferric salicylate complex is changed by the addition of minute quantities of citrate, tartrate, or any other substance capable of repressing the ferric ion. The absence of hydrogen tartrate in amounts not less than 1 in 8x104, 25 × 104, and 12.5 × 104, respectively, can be shown by this method. L. L. BIRCUMSHAW.

Systematic detection of traces of aldehydes. E. Č. CROCKER (Ind. Eng. Chem., 1925, 17, 1158— 1159).-See B., 1925, 1011.

Specific action of carbonic acid on the respiratory centre in man and rabbits. S. HETÉNYI, J. HOLLÓ, and S. WEISS (Biochem. Z., 1925, 160, 242245). After injection of 20 c.c. of normal sodium hydrogen carbonate solution into man, a lowering of the acidity of the blood and of the alveolar carbon dioxide tension is found. In experiments with rabbits, injection of mixtures of hydrogen carbonate and carbonic acid of acidity either corresponding to, or somewhat more acid than, that of the animal's blood, displaces the pH of the blood slightly to the alkaline side. P. W. CLUTTERBUCK.

Metabolism in rarefied air. I. Gas metabolism and protein metabolism. W. LAUBENDER (Biochem. Z., 1925, 162, 459-468).-Experiments with guinea-pigs living in a chamber under reduced pressure (430-380 mm. of mercury) show that decrease in weight is smaller than in the control experiment; that during the first 2-6 hrs. there is a 20-40% increase in carbon dioxide elimination, the oxygen utilisation being, however, unaffected; that after the first 12-24 hrs. there is a 5-30% reduction in gaseous exchange; that there is a 14-59% increase in total nitrogen eliminated in the urine, and that during the

second stage of the experiment the ammonia coefficient decreases. P. W. CLUTTERBUCK.

Respiration and glycolysis in animal tissues. R. O. LOEBEL (Biochem. Z., 1925, 161, 219–239).— The glycolysis and respiration of the grey matter of rats' brains and of the spinal cord of frogs is compared with the carbohydrate metabolism of muscle and carcinoma cells. Narcotics inhibit respiration to a greater extent than glycolysis in nervous tissues, carcinoma cells, and growing epithelium. The effect is more pronounced with the higher members of a homologous series. Sodium fluoride, on the other hand, depresses glycolysis more than respiration.

The glycolytic behaviour of different sugars is similar in nervous and carcinoma cells, but differs sharply in the case of muscle. Lactic acid is produced from dextrose and mannose, to a lesser extent from hexosephosphoric acid, and not at all from glycogen, lævulose, maltose, or trioses. Respiration in absence of sugar decreases to about 10% or 20% of its original intensity in 2 hrs., but this is restored equally well by dextrose or lævulose. Although the trioses are unable to increase respiration, yet lactic and pyruvic acids will restore this when its intensity has fallen.

C. RIMINGTON.

Gas and electrolyte equilibria in blood. VIII. Distribution of hydrogen, chloride, and hydrogen carbonate ions in oxygenated and reduced blood. D. D. VAN SLYKE, A. B. HASTINGS, C. D. MURRAY, and J. SENDROY, jun. (J. Biol. Chem., 1925, 65, 701– 728). The activity coefficient of hydrogen carbonate ions in horse-serum, calculated from the experimentally determined apparent dissociation constant and the real constant (cf. Hastings, and Sendroy, this vol., 25), is 0.63, which gives 0.16 for the ionic strength of the serum; the latter value agrees closely with that calculated from analyses of serum; in the case of the cell contents, there is a discrepancy, at present not explained, between the activity coefficient demanded by the calculated ionic strength (0.62) and that found (0-40). A study of the distribution of ions between cells and serum in reduced and oxygenated blood indicates that for the range of p 707.6 the changes in distribution with changes in reaction are in agreement with those predicted by Van Slyke, Wu, and McLean (A., 1923, i, 1249); the actual ratios

are

related as follows: [cells: []serum=0.77X {[Cl]cells [CI]serum} = 0.62 x {[HCO3lcells: [HCO3]serum}, where a represents the activities of the hydrogen ions, and [CI] and [HCO3] the molar concentrations of chloride and hydrogen carbonate. The fact that the difference in the magnitude of the latter ratios was not previously observed is accounted for by the previous lack of a method for determining the chlorides of the cells; this is now done with accuracy by the method of Van Slyke and Sendroy (A., 1924, ii, 271). C. R. HARINGTON.

Reconversion of methæmoglobin into oxyhæmoglobin. II. Perfusion experiments. III. Experiments on the living animal. K. SAKURAI (Arch. exp. Path. Pharm., 1925, 109, 198-213, 214— 232).-II. If the blood perfused through an isolated lung contains more than 70% of methæmoglobin, scarcely any conversion of the latter into oxyhæmoglobin can take place; if the concentration is 60% or less, such conversion takes place to the extent of 26% if ordinary air be breathed; the degree of conversion is increased by breathing hydrogen, by the addition of sodium thiosulphate to the blood, and by inclusion of the liver in the circulation; in the most favourable circumstances it is still less than 50%.

III. The toxic symptoms of poisons such as aniline and sodium nitrite, which exert their effect by formation of methæmoglobin, can be relieved to some extent, in cats, by intravenous administration of sodium thiosulphate; the favourable effect of thiosulphate could not be observed in rabbits.

C. R. HARINGTON.

Do ammonium salts exist in the blood? G. FONTÈS and A. YOVANOVITCH (Bull. Soc. Chim. biol., 1925, 7, 1044-1055).-Only minimal amounts of ammonium salts (0·05-0.1 mg. per litre) are found in fresh venous or arterial blood, and it would appear that in the circulating blood no ammonium salts exist. The ammonia in the blood gradually increases with the time after withdrawal from the body. The biological consequences of the non-existence of ammonium salts in the circulating blood are discussed. W. O. KERMACK.

Isolation of a new substance from blood and its bearing on determination of uric acid. G. HUNTER and B. A. EAGLES (J. Biol. Chem., 1925, 65, 623-642).—By treatment of the protein-free filtrate from red blood-corpuscles with alcoholic mercuric chloride, fractional precipitation of the solution obtained on recovery from this precipitate with lead acetate and sodium hydroxide, removal of the lead from the precipitate with sulphuric acid, and treatment of the resulting solution with mercuric sulphate, there was obtained, from 5.5 litres of corpuscles, 0.7 g. of a substance, CH1103N2, darkening at 250°, m. p. 269-270°, [a] -115°. The substance is neutral, takes up bromine and decolorises alkaline permanganate, gives Weyl's reaction, and is resistant to acid hydrolysis, being unchanged by heating at 140° for 4 hrs. with 20% sulphuric acid; with nitrous acid, it gives traces only of nitrogen; it is suggested that the compound is a simple pyrimidine nucleoside. The substance gives a blue colour with the reagents used for the determination of uric acid, and its presence accounts for the discrepancies observed between determinations by the method of Benedict (A., 1922, ii, 405) and that of Folin and Wu (A., 1919, ii, 308). (Cf. Bulmer, Eagles, and Hunter, A., 1925, i, 605.) C. R. HARINGTON.

Sugar content of blood. B. K. HARNED (J. Biol. Chem., 1925, 65, 555-560).-Precipitation of the proteins of blood with mercuric nitrate in nitric acid and removal of excess of mercury from the filtrate with hydrogen sulphide yields a solution entirely free from organic nitrogenous compounds; determinations of dextrose in such fluids by the method of Folin and Wu (A., 1920, ii, 337) give results in close agreement with those obtained by the recent method of Benedict (A., 1925, i, 994) and therefore probably represent the

true concentration of dextrose. C. R. HARINGTON.

Dextrose content of human erythrocytes. P. A. TEDESCO (Folia med., 1924, 10, 561-571; from Chem. Zentr., 1925, II, 939).-Human red blood-corpuscles are permeable to dextrose, yet their dextrose content is always less than that of the G. W. ROBINSON. plasma.

Determination of dextrose, non-protein nitroblood of man in tropical regions and in the blood gen, uric acid, and total phosphorus in normal of birds suffering from avitaminosis. P. J. T. VAN BERKHOUT (Arch. Néerland. physiol., 1925, 10, 303-322).-See A., 1925, i, 453.

Action of calcium on the acid-base equilibrium in man. J. HOLLÓ and S. WEISS (Biochem. Z., 1925, 160, 237-241).-Intravenous injection of hypertonic calcium chloride solution decreases the hydrogen carbonate content of the plasma and increases the alveolar carbon dioxide tension and acidity of the blood. Calcium chloride and lactate administered orally also decrease the hydrogen carbonate content of the plasma, but an effect on the tension of carbon dioxide and on acidity of blood could not be detected with certainty.

P. W. CLUTTERBUCK.

Influence of calcium salts on serum calcium of normal and thyroparathyroidectomised dogs. A. M. HJORT (J. Biol. Chem., 1925, 65, 783-795).A constant increase in the calcium of the bloodserum, following oral administration of calcium salts to dogs, could be obtained only by doses of soluble calcium salts in amounts equivalent to 0.2727 g. of calcium oxide, or more, per kg. of body-weight. Doses of this magnitude raised the concentration of calcium in the serum, and hence relieved the symptoms of tetany, in thyroparathyroidectomised dogs.

C. R. HARINGTON.

Action of metallic salts on the capacity of blood to decompose hydrogen peroxide. L. BLEYER (Biochem. Z., 1925, 161, 91-103). In comparing the action of different salts, the pH of the solution cannot be neglected. In the majority of instances inhibition of the catalase occurs, this being least marked with the alkali chlorides, but no relation between inhibition and valency can be detected.

By graphic representation of the inhibition (ordinate) produced by different concentrations (abscissa), there is obtained for each salt a curve closely resembling the dissociation curve of an acid. The time curve of the catalytic action of sodium molybdate approximates to a parabolic function (k=x/√t). With catalase also present, no summation effect occurs, the velocity being less than that of the control. Ferric chloride in concentrations up to 0.0001 M has a stimulating influence on catalase.

The reaction velocity in presence of lanthanum chloride, strontium nitrate, and potassium antimonite still corresponds with Morgulis' equation (A., 1921, i, 751); these substances do not therefore decrease the active concentration of the enzyme, although inhibition occurs in their presence. C. RIMINGTON.

Buffering properties of serum proteins. K. GOLLWITZER-MEIER (Biochem. Z., 1925, 163, 470475). The relation of carbon dioxide combining power to carbon dioxide tension was determined for serum, serum ultrafiltrate, and ultrafiltrate residue. The results lead to the conclusion that, in the physiological range, the buffering of the serum depends chiefly on the serum proteins.

The

ously clotting blood are irregular during the first 4-5 hrs., but that the concentration then increases regularly up to 24 hrs. The view that plasma serum contains a higher protein concentration than serum of whole blood could not be confirmed. refractivity of dilute sodium citrate solutions increases proportionately with increasing strength, but at higher concentrations the increase of refractivity becomes less and less. By addition of sodium citrate (0.2%) to whole blood, incorrect plasma values were obtained and addition similarly to serum did not give a purely additive increase in refractivity. The viscosity increase when increasing amounts of sodium citrate are added to serum does not keep pace with sodium citrate to the serum has, however, correspondthe increase in refractivity. Addition of isotonic sodium citrate to the serum has, however, corresponding effects on both refractivity and viscosity. When mended for the determination of fibrinogen. hirudin is not available, Starlinger's method is recomP. W. CLUTTERBUCK.

Relative viscosity of proteins of human bloodserum and their determination. W. STARLINGER and K. HARTL (Biochem. Z., 1925, 160, 225–236).— A critical study of a number of methods for the determination of the relative viscosity of serum proteins. P. W. CLUTTERBUCK.

Abderhalden's reaction. A new blood reaction. H. SELLHEIM (Vox Medica, 1925, 1, 128-141; from Chem. Zentr., 1925, II, 1078).— Abderhalden's reaction as modified by Lüttge and Mertz (B., 1925, 259) is discussed. Amongst the applications of the method are the study of nutrition, of cancer, and of changes during pregnancy, the examination of spinal fluid, and the determination of the degree of decomposition of meat.

G. W. ROBINSON.

Reversible hæmolysis. L. BOGEN DÖRFER and B. HALLE (Biochem. Z., 1925, 160, 199-209).— The methods of reversible hæmolysis of Brinkman and Szent-Györgyi are used to effect the combination of hæmoglobin and stroma of different origin and of different kinds of animals. Red blood-corpuscles after hæmolysis and reversion become more resistant to hypotonic solutions. The adsorption of hæmoglobin from solution by foreign stroma may be seen refractometrically. The authors support the view that hæmoglobin is adsorbed on the stroma. P. W. CLUTTERBUCK.

Detection of enzymic processes conditioned by immunisation. III. E. KUPELWIESER and E. NAVRATIL. IV. E. KUPELWIESER and I. WILHEIM

(Biochem. Z., 1925, 160, 75-87, 88—100).—III. Sera guinea-pigs which had received preliminary treatobtained during the anti-anaphylactic condition from ment with active horse-serum as antigen, were investigated by the refractometric method for the presence of specific proteolytic action on the antigen, with entirely negative results. (Cf. A., 1924, i, 806.)

IV. The possibility that the refractometric method failed to detect products of proteolytic action because the products were adsorbed on the intact substrate and thus did not go into solution, is dismissed in view

of the results of a series of adsorption experiments under similar conditions. P. W. CLUTTERBUCK.

Salkowski's method of preparing protein-free anti-toxin solutions. H. DOLD and E. FREUDENBERG (Biochem. Z., 1925, 162, 169-170).-A criticism of Salkowski's preparations, which were found to be not entirely free from protein. H. G. REEVES.

Salivary glands. II. Occurrence of glycogen with reference to the excretion of sugar and glycogen. S. YAMAGUCHI (Beitr. pathol. Anat. allgem. Pathol., 1924, 73, 123-141; from Chem. Zentr., 1925, II, 1055).-Glycogen was absent from the salivary glands of human and canine fœtuses, and from the excretory ducts of new-born and of adult rats. It was present only in small quantities in the case of pregnant rats. From experiments with pancreatectomy, and injection of sugar or adrenaline, the author concludes that the salivary glands play an important part in the excretion of glycogen and sugar. They can excrete these substances under the same conditions as the kidneys. The lachrymal glands and other organs (uterus, bronchi) may also participate G. W. ROBINSON.

to some extent.

Distribution of injected sulphates in tissues. W. DENIS and S. LECHE (J. Biol. Chem., 1925, 65, 565-570).—Considerable variations were observed in the sulphate content of normal tissues. Intravenous

injection into dogs of large amounts of hypertonic sodium sulphate solution produced a marked and prolonged rise in the concentration of sulphates in the blood but no definite change in that in the tissues. C. R. HARINGTON.

Body-content of the hedgehog during hibernation. E. WEINLAND (Biochem. Z., 1925, 160, 6674). Determination of the fat, glycogen, nitrogen, and water content of the hedgehog at various times during hibernation are tabulated.

P. W. CLUTTERBUCK.

Mucoproteins of snails, Helix aspersa and H. pomatia. P. A. LEVENE (J. Biol. Chem., 1925, 65, 683-700). From the mucoprotein of the mucus of these two species there was obtained in each case, by treatment with alkali followed by precipitation with alcohol, a substance which is soluble only in strong mineral acids, gives a positive reaction for glycuronic acid, and reduces Fehling's solution only after hydrolysis; it is therefore a mucoitinsulphuric acid; on partial hydrolysis, it yielded mucosin (which on disstillation with hydrochloric acid gave the theoretical amount of furfuraldehyde), and on complete hydrolysis chitosamine, and a volatile fatty acid which was probably acetic acid. By similar treatment of the mucoprotein of the foot of the snail, the glucoprotein of the body, or by direct extraction of the body, there was obtained, in addition to the above mucoitinsulphuric acid, a polysaccharide ("animal gum "), which on hydrolysis gave galactose and acetic acid, and, on oxidation with dilute nitric acid, yielded mucic acid, and therefore appears to be an acetylated polygalactose. C. R. HARINGTON.

Transformation products of the pigments of flesh and blood. VI. Kopratin, a substance derived from a-hæmatin by intestinal putrefaction, and the related porphyrin. O. SCHUMM (Z. physiol. Chem., 1925, 149, 1-18).-If food containing blood pigments is eaten, or blood reaches the intestine from internal bleeding, together with a-hæmatin itself, another pigment which is derived from a-hæmatin by putrefaction appears in the fæces. This pigment, kopratin, may be separated from fæces by extraction with pyridine. On treatment of the pyridine extract with a little hydrazine hydrate, a solution is obtained having a well-marked absorption band at 545. It does not occur in the fæces of healthy individuals on a diet free from blood. It also appears to be produced outside the body during putrefaction of blood. The corresponding porphyrin is obtained by treatment of kopratin with hydrazine hydrate in glacial acetic acid solution. Methods of isolation of kopratin are described. H. D. KAY.

R.

It is

Bile pigments. XVII. Copper bilirubin. HAAS, H. MAURER, and W. KÜSTER (Z. physiol. Chem., bilirubin, in ammoniacal solution, to give a copper 1925, 149, 30-43).-Copper salts combine with compound of bilirubin which may be precipitated from the reaction mixture with acetic acid. It occurs benzoate, the other from hot pyridine solution. in two modifications, one obtained from hot ethyl a very stable salt, and may be esterified direct with boiling methyl alcohol and hydrochloric acid without firmly united and is only very slowly precipitated by breaking up the bilirubin molecule. The copper is sodium sulphide and not at all by potassium ferrocyanide. Copper bilirubin may be benzoylated in pyridine solution, yielding a benzoyl compound which contains 4 mols. of pyridine very firmly attached. By reduction with sodium amalgam, copper bilirubin yields mesobilirubinogen.

H. D. KAY.

Pigments. B. BLOCH and F. SCHAAF (Biochem. Z., 1925, 162, 181-205).-Melanin is formed in the protoplasm of pigment cells (ectodermal and mesodermal melanoblasts) from a colourless precursor by means of an intracellular oxidation ferment, "dopaoxydase," which may be detected by the "dopareaction tion" (conversion of 3: 4-dihydroxyphenylalanine into "dopamelanin "). It is sensitive to heat, drying, and hydrogen sulphide, but only slightly to hydrogen cyanide. It is very specific and its optimum pH is 7.3-7.4. Pigment formation and the presence of the enzyme run parallel. The absorption spectrum of dopamelanin shows no characteristic bands, absorption beginning in the visible spectrum and increasing continuously with decreasing wave-length. Dopamelanin is a negative colloid and is best precipitated by acid, aluminium sulphate solution, or colloidal ferric hydroxide. Its solubility in alkalis, water, alcohol, and pyridine varies with the method of preparation and drying. It is very resistant to oxidation and reduction, and the products obtained by energetic reagents are not characterised. Dopamelanin is prepared by oxidation of 3: 4-dihydroxyphenylalanine with oxygen in alkaline solution, carbon dioxide being eliminated. The original nitrogen of the amino-group was in part removed as

ammonia and in part converted into another form no longer determinable by Van Slyke's method. The amount of nitrogen obtained as ammonia is about half of the amino-nitrogen disappearing. This deamination occurs, therefore, without the presence of a deaminase and without the assistance of iron (the reaction follows the same course in the presence of potassium cyanide). The nitrogen content of dopamelanin varies in different preparations from 5% to 8%, the purest product containing 5.23%. The proportion between the amino-nitrogen (Van Slyke) and the total nitrogen in both natural and artificial melanins is smaller the purer the preparation, the quotient in the purest artificial sample being 1/15.5. The author concludes that the small amino-nitrogen content of all

specimens of melanin is due to adsorption during purification of intermediate products of oxidation. P. W. CLUTTERBUCK.

Pigment studies in connexion with a case of ringed hair. K. KLINKE (Biochem. Z., 1925, 160, 28-42).-Determinations of the sulphur, nitrogen, cystine, tyrosine, and tryptophan contents of a number of types of hair were made, including a case of "ringed hair in which the hair cylinder is alternately lightly and darkly pigmented. The whole of the sulphur of normal human hair is present as cystine. Red hair contains, however, more sulphur than is represented by the cystine value. The colour of hair does not depend directly on the sulphur or the cystine content, but more probably on the tyrosine content. Whereas normal hair contains 4.3% of tyrosine, red and "ringed" hair contain 5.3-6.2% White flaxen hair contains only 3.8% of tyrosine and 0.6% of tryptophan. The gas in the air-containing chambers of ringed" hair contains 5.4% of oxygen and 2% of carbon dioxide. P. W. CLUTTERBUCK.

Reducing and iodine-combining power of urine. I. In normal individuals. H. K. BARRENSCHEEN and L. POPPER (Biochem. Z., 1925, 161, 210-218).-The urinary substance described by Moor (A., 1924, i, 1134; 1925, i, 328) does not exist, the properties attributed to it being due to the accompanying pigments. In normal urine, the reducing power is parallel to the pigment content, but is unrelated to the iodine value. In the presence of glacial acetic acid, this latter value falls to the extent of about 9-29%, no alteration in reducing power occurring. The residual iodine uptake is related to the amount of urobilinogen present.

and calcium chlorides is injected intravenously into an anesthetised dog, the quantity of water secreted by the kidney is increased, but there is no constant increase in the concentration of chloride in the urine, such as was observed by Starling and Eichholtz in a heart-lung-kidney preparation (Eichholtz and Starling, Proc. Roy. Soc., 1925, B, 98, 93). When, however, the pituitary body was removed, so that the kidneys had lost their power of concentrating the chlorides, results were obtained on the intact animal precisely similar to those of Starling and Eichholtz, the chloride in the urine secreted being constantly increased after injection of a mixture of calcium and potassium ions. W. O. KERMACK.

kidney. II. Influence of the pituitary gland Secretion of inorganic phosphate by the

L. BRULL

and of the wall of the third ventricle. and F. EICHHOLTZ (Proc. Roy. Soc., 1925, B, 99, 70-91).-Excision of the pituitary body, or injury to the tuber cinereum, results in the loss by the kidney of the ability to secrete inorganic phosphates, whether or not denervation of the kidney has taken place. If, however, the inorganic phosphate in the blood is raised by injection of sodium phosphate, that ion appears in the urine when its concentration in the blood exceeds a certain critical value. Intravenous injection into an animal with intact pituitary and tuber cinereum, of sodium or potassium, or small quantities of calcium chloride, results in an increased secretion of urine, and an increase in the amount of inorganic phosphate secreted, although this increase is less than corresponds with the increase in the amount of urine. Large quantities of calcium chloride, on the other hand, cause a decrease, or even complete cessation of phosphate output. W. O. KERMACK,

Hydrolysis of phosphoric esters by the kidney in vivo. F. EICHHOLTZ, R. ROBISON, and L. BRULL (Proc. Roy. Soc., 1925, B, 99, 91-106).— When a heart-lung-kidney preparation is perfused with defibrinated blood containing sodium glycerophosphate, inorganic phosphate appears in considerable, although variable, quantities in the urine. This is not due to the increase in inorganic phosphate of the circulating blood, nor to hydrolysis in the urine after secretion of organic phosphate, but it seems to be caused by hydrolysis in the kidney cells by the enzyme described by Robison (A., 1923, i, 730) as being present in the kidney, as well as in calcifying bone. Decrease of the pH of the circulating blood results in a decrease in the inorganic phosphate in the urine. This is to be expected as a result of the high optimum pH of the enzyme. When sodium glycerophosphate is injected into an intact animal from which the pituitary body has been removed (cf. preceding abstract), inorganic phosphate is excreted in the urine in high concentration, and the injected sodium glycerophosphate rapidly disappears from the blood. It is suggested that the normal secretion of phosphate by the kidney is dependent on the activity of the W. O. KERMACK.

enzyme.

Botelho's reaction. F. FALUDI (Biochem. Z., 1925, 162, 116-127).-The reaction is essentially a protein precipitation test; it is independent of the