PHYSIOLOGICAL CHEN ISTRY. 59 Physiological Chemistry. OxygenTension of Arterial Blood, By JOHN S. HALDANE and J. LORRAIN SMITH (J. Physiol., 1896, 20, 497--520).-The aeroto- metric method of estimating the oxygen tension in blood is open t o many objections that are pointed out, The value of the present method is accentuated by the fact that it is applicable to animals and men during life. The subject breathes air containing a small known amount of carbonic oxide until the percentage saturation of his hEmoglobin with that gas is constant, The final saturation with carbonic oxide of hEmoglobin solutions can be determined with quite small quantities of blood from the finger by a method previously described ; it depends on the relative tensions of carbonic oxide and oxygen in the liquid, so that if the tension of carbonic oxide and the final saturation of the hRmoglobin are known, the oxygen tension can be inferred.Full details of the method of titration with carmine and a few necessary corrections are given. It was proved that the oxygen tension of human arterial blood is 26.2 per cent. of an atmosphere or 200 mm. of mercury ; as this is higher than the tension of oxygen in the alveolar air, diffusion alone will not explain the passage of oxygen from the alveolar air to the blood, Carbonic oxide is not oxidised in the body. W. D. H. Muscular Power and Gaseous Metabolism. By LOUIS SCHNYDER (Zeits. Biol., 1896,33, 289-319).-The increased discharge of carbonic anhydride that occurs during work is lessened by practice. The amomt of decomposition of tissue depends on the extent of the exertion rather than of the work done.I n normal individuals, the involuntary muscles are already in a state of “training,” and in weakened convalescents these work with abnormal exertion even during so-called rest. W. D. H. The Lowest Limit of Nitrogenous Equilibrium. By ERWIN VOIT (Zeits. Biol., 1896, 33, 333--351).--This paper is principally polemical. I n it, with a few new experiments, C. Voit’s original teaching is confirmed, and Munk’s criticisms on this work combated. W. D. H.60 ABSTRACTS OF CHEMICAL PAPERS. Influence of Fat on Nitrogenous Metabolisrn. By A. WICKE and HUGO WEISKE (Eeits. physiol. C h n . , 1896,22, 265-277. Compare Abstr., 1895, ii, 516 ; 1896, ii, 198, 535).-This is a continuation of previous work.The general conclusions are that in herbivora (sheep), gradually increasing doses of fat added to a rich proteid diet cause a smaller nitrogenous assimilation, and the output of nitrogen gets less until equilibrium is established. This has a limit which was reached in the authors' experiments when the daily dose of fat amounted to 150 to 180 grams ; beyond that, nitrogenous metabolism is increased. W. ID. H. Preparation of Pepsin. By CORNELIS A. PEKELHARING (Zeds. p?t,ysiol. Chem., 1896, 22, 233-244).-A very powerful preparation of pepsin is obtained by dialysing artificial gastric juice against distilled water ; the pepsin is precipitated, redissolved in dilute hydro- chloric acid, and reprecipitated by dialysis. There is much loss of material in the process.It gives the proteid reactions and contains phosphorus (less than 1 per cent.). This may be in the pepsin or in a nucleo-proteid mixed with the pepsin, but it is not due to admixture with lecithin. By heating a solution, the phosphorus-containing sub- stance is precipitated, and proteose goes into solution. The quantity of phosphorus in this nucleo-proteid is less (0.3 per cent.) than in the original substance ; some unknown phosphorus-containing substances passing into solution. The activity of this pepsin is destroyed by alcohol, or by heating it to the temperature (60-70") to which the precipitation just described occurs. If commercial pepsin is digested with 0.3-0.5 per cent. hydro- chloric acid, even for 5 days, it still continues to curdle milk.This is contrary to Hammars t en's st a t emen t . The nuclein yields alloxuric bases. W. D. H. Bromine in the Animal Body a f t e r the Administration of Bromine Compounds. By WERNER ROSENTHAL (Zeits. p?t,ysiol. Chem., 1896, 22, 227--232).-Four dogs were fed on Paal's hydrogen- bromide-peptone added to flesh and milk. There were no toxic symptoms. After death, bromine was found in the thyroid (small quantities occur with iodine in the normal thyroid), liver, spleen, hair, pancreas, muscles and kidney in small quantities. About the same quantity is found when potassium bromide is given. W. D. H. Effects of the Injection of Peptone into the Circulation. By WILLIAM H. THOMPSON (J. Physiol, 1896, 20, 455-473).-1n dogs, Witte's " peptone," in doses below 0.02 gram per kilo.of body weight, produces hastening of coagulation; above this dose, it causes re- tardation, as others have found. I n doses as low as 10-15 milli- grams per kilo, it causes a fall of blood pressure when the rate of injection is rapid; this is due to vascular dilatation by a direct influence on the blood vessels of the splanchnic and other areas. No indirect influence through the vaso-motor centre was observed, thePHYSIOLOGICAL CHEMISTRY. 61 results found being practically the same even after severance of the cervical cord. W. D. H. Action of Carbonic Anhydride on Muscle. By AUGUSTUS D. WALLER and Miss S. C. M. SOWTON (PYOC. PhqsioZ. Soc., 1896, 16--17).-1n ordinary striped muscle, stimulation in the presence of carbonic anhydride results in the staircase phenomenon.The con- clusion is drawn that this phenomenon is due, as in nerve, to the evolution of the gas during contraction. With heart muscle, the effect, however, of stimulation is simply decrease in contraction and electrical response; there is no augmentation or staircase at first. Ether and chloroform act similarly. By CORNELIS a. PEKELHARING (zeds. p?~y~sioI. Chem., 1896, 22, 245-247).-Whitfield’s (Abstr., 1894, ii,, 358) failure to obtain nucleo-proteid from muscle is due (1) to the fact that he used water as the extracting agent; tohis rapidly becomes acid, and nucleo-proteids are insoluble in dilute acids ; (2) gastric digestion, if the quantity of nuclein is small and the percentage of hydrochloric acid over 0.1, may not give rise to a precipitation of nuclein.I n the present research, the muscles of various animals were used ; the extracting agent was 0.25 per cent. solution of sodium carbonate. From the extract, which contains very little myosin, a nucleo- proteid is precipitable by acetic acid, two grams were obtained from 543 grams of flesh; it causes intravascular clotting, and contains 0.7 per cent. of phosphorus; its nuclein contains 3.5 per cent. of phosphorus and yields the alloxuric bases xanthine and guanine in small quantities. W. D. H. Occurrence of Inosite in the Thyroid Gland. By R. TAMBACH. (J. P?LCC~WL, 1896 [6], 4, 119.)-This substance appears to occur in larger quantity, from 0.6 to 0.8 per cent., in the thyroid gland than in any other part of the body. By SIGMUND FRANKEL (Wien.med. Blatter, 1896, Nos. 13, 14, 15).-The paper gives further particulars regarding the metallic compounds of thyreo-antitoxin (Abstr., 1896, ii, 119). A second base was also separated from the proteid free extract of the gland. The gland contains a considerable quantity of inosite. The conclusion of Drechsel and Kocher, that the organ forms more than one physiologically active substance, is supported. T.V. D. H. Nucleo-proteid in Muscle. M. W. T. Chemistry of the Thyroid. W. D. H. Chemistry of the Thyroid Gland. By ROBERT HUTCHISON (J. Physiol , 1896, 20, 474--496).-The thyroid contains two proteids, a nucleo-albumin, and the colloid matter; the former is present in small amount, and is probably derived from the epithelium. It mas prepared by Halliburton’s sodium chloride method.The colloid is contained in the acini. It contains a small amount of phosphorus and a considerable proportion of iodine ; it yields no reducing substance on treatment with mineral acids, and no nuclein bases and is, there- fore, neither a mucin, nor a nucleo-proteid. On gastric digestion, it is62 ABSTRACTS OF CHEMICAL PAPERS. readily split into a proteid and a non-proteid part ; both of these, but especially the latter, contain iodine. The non-proteid part contains all the phosphorus of the original substance. The ordinary extractives are fairly abundant; but the colloid is the active physiological con- stituent of the gland ; both parts of it are active, but the non-proteid part is the more active of the two. W. D. H. Chemistry of the Much of the Respiratory Tract.By FRIEDRICH MULLER (Cent?. Plu~sioZ., 1896, 10, 480-481, from Sitz. Ges. Bef+d. Natzww. Mcwburg, 1896, No. 6).-The mucin of sputum was prepared by solution in alkali, and precipitation by acid and subsequently by alcohol ; it is free from nuclein. After treatment with dilute sulphuric acid, it yields from 25 to 32 per cent. of a reducing substance ; this is not a pentose, and the hexose prepared from it could not be identified with any known sugar; probably it may be glucos- nmine. W. D. H. The Nucleins of Pus. By EXILE LEIDI~ (J. Ph'??Z., 1896 [6], 4, 150--155).-The nucleins appear to be a class of substances which differ widely amongst themselves in composition, and in the manner in which they decompose. This investigation was undertaken for the purpose of comparing the nucleins of purulent urine with those obtained from other sources.A mixture of alkali-albumins and nucleo- albumins was obtained by a method described in another paper (next abstract), and from this a nuclein. The results of the estimation of sulphur, phosphorus, and nitrogen in this substance a$reed closely with those ohtained by Hoppe-Seyler for a nuclein from another source. M. W. T. The Proteids of Purulent Urine (Pyin and Mucin). By EMILE LEIDI~. (J. Phmm., 1896 [6], 4, 97--103).-The author considers that the two substances, mucin and pyin, which are usually taken as indicating the presence of pus in urine, are not original17 present in the pus, but are produced by the action of alkalis on its constituents. When purulent urine, which has usually a slightly acid character, is preserved from contact with air, the leucocytes remain intact, and the liquid is found to contain neither much nor pyin.When the urine undergoes ammoniacal fermentation, the leucocytes quickly break up, and dissolve in the liquid. The liquid now contains both mucin and pyin, which, however, cannot be said to be derived from the broken down leucocytes, as the quantity increases with the duration of fermentation. Pyin appears to be an alkali-albumin, and the mucin of acid purulent urine a nucleo-albumin, whilst the so-called mucin of the mucus of the bladder is probably a mixture consisting principally of a globulin. M. W. T. Proteids of Milk and the Methods for their Separation. By A. SCHLOSSMANN (Zeit.physiol. Clzm., 1896, 22, 197--226).-A criticism on the methods at present in use for the separation and estimation of the proteids in milk. A new method is also recom- mended ; it Consists in adding to the milk a small quantity of a saturatedPHYSIOLOGICAL CHEMISTRY. 63 solution of potassium alum a t 37”. This precipitates the caseinogen in an insoluble form, and leaves the albumin and globulin unprecipi- tated. The globulin is precipitated from the filtrate by magnesium sulphate, and the albumin determined by difference. I n cows’ milk, the numbers given are : caseinogen 3.185, globulin 0.154 and albumin 0.374 per cent. The importance of the albumin and globulin in nutrition is insisted upon. This is true for human, cows’, asses’, and pigs’ milk. W. D.H. Action of Rennet. By R. BENJAMIN. (Vi~clbow’s Archiv, 1896. 145, 30-48).-This work is largely a criticism of Peter’s researches (Abstr., 1895, ii, 80. Compare also Hammarsten, Abstr., 1896, i, 583, Edmunds, ibid., ii, 489). The conclusions drawn are that rennet acts only on the caseinogen of milk and on no other proteid of either animal or vegetable origin ; solutions of caseinogen fermentable in this way are, like milk itself, alkaline to lacmoid and acid to phenolph- thalein; a caseinogen solution is only coagulable in the presence of soluble calcium salts. W. D. H. Estimation of Sulphur in Animal Tissues, and in the Hair of Animals of different Ages, By FRANZ D~RING. (Zeits. physiol. Chem., 1896, 22, 281--284).-Sulphur was estimated in the hair of men and animals, in hoofs, and in rabbits’ flesh; the method used being a modification of Hoehnel-Glaser’s.The results are very close to those of Mohr (Abstr., 1895, i, 255). The percentage of sulphur in rabbits’ hairs a t different ages was also investigated ; the numbers lie between 3.9 and 4.6 per cent., but there is no such marked variation with age as Weiske (Lundw. Versuchs-Stat, 36, 81) found in birds’ feathers. W. D. H. Physiological Action of Nitrites. By JOHN S. HALDANE, R. E. MAKGILL and A. E. MAVROGORDATO. (Proc. Yhysiol. Soc., 1896, l$).- Nitrites convert the haemoglobin of the blood into a mixture of methsmoglobin and nitric-oxide-hzemoglobin. I n excess, amylic ni- trite causes the appearance of photomethzemoglobin. Death caused by nitrites is due simply t o their action on haemoglobin. I f the oxygen in the blood plasma is simultaneously increased by administra- tion of the gas a t high pressure, this is sufficient to support life, in spite of the fact that the haemoglobin is no longer capable of carrying oxygen.The experiments were made on mice and rabbits, and are similar in plan and results to those previously described in carbonic oxide poisoning (Abstr., 1895, ii, 407, also 1896, ii, 52). W. D. H. Physiological Action of the Suprarenal Capsules. By SIGMUND FRANKEL (Viern. med. Blatter, 1896, Nos. 14, 15, 16).-The main action of an extract of the medulla of the suprarenal capsules when injected into the circulation is a rise of blood pressure. This is due t o peripheral action on the small vessels, as Schafer and Oliver (Abstr., 1895, ii, 235) showed; and as Moore (ibid., 236) stated this is due to a reducing substance originally described by Vulpian.The present research is directed to an examination of this substance; this was64 ABSTRACTS OF CHEMICAL PAPERS. separated by extraction with alcohol and acetone, but not crystallised. The name spggnzogenin is suggested for it. Its chemistry is not yet fully worked out, but its reactions point to its being a nitrogenous derivative of the ortho-dihydroxybenzene series. W. D. H. The Significance of Chlorides in Anemia. By WACLAW VON MORACZEWSKI (Vi~chow’s Archiv, 1 896, 145, 458--4SO).-During antemia, there is a diminution in the excretion of chlorides in the urine; the excretion increases as the patient gets better. Calcium phosphate behaves like the chlorides. The alkali phosphates and uric acid fire increased in amount in the urine in the ansmic periods ; this increase lessening with convalescence. An addition of calcium phosphate and sodium chloride to iron salts increases their blood- forming action. W. D. H. By FREDERICK W. PAVY ( Z‘YOC. Plu~siol. Soc., 1896, 19--22).-The statement has been made that in phloridzin diabetes there is no glycohsmia. The present communication shows that if fallacies in the collection of blood, in the use of anmthetics, and in the method employed for analysis of the blood, be avoided, there is a distinct rise in the percentage of sugar in the blood as a result of giving the drug. Phloridzin Diabetes. W. D. H. Action of Carbon Bisulphide on Hzemoglobin. By KICOLAI KROMER (Fi~chow’s A d & , 1896, 145, 188-19O).-Death produced by carbon bisulphide is due t o paralysis of the respiratory centre, not to any change in the blood pigment, for although t h i s reagent causes, after the lapse of time, a partial precipitation of proteid matter, the spectrum seen is that of oxybamoglobin. This occurs in experi- ments performed in the living body and in vitro; there is no formation of methemoglobin or hsmatin, as some observers hare described. W. D, H,