PHYSIOLOGICAL SOCIETY, PROCEEDINGS No. III. Prof. HALLIBURTON made a communication on the chemical characteristics

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1 PROCEEDINGS OF THE PHYSIOLOGICAL No. III. SOCIETY, KING'S COLLEGE, LONDON. March 12. Chemical Characteristics of Nucleo-albumivs. Prof. HALLIBURTON made a communication on the chemical characteristics of nucleo-albumins. He had ascertained that some of the proteids he had described in liver, kidney, and brain, in previous communications to the Society, as globulins, were in reality nucleoalbumins; that is on gastric digestion they yielded not only proteoses and peptone, but also an insoluble product rich in phosphorus, nuiclein. He had since this been engaged in studving the properties of -iucleo-albumins. Two mnethods of preparing these substances were used:-(a) the finely minced organ was mixed with a strong solution of sodium chloride; the resulting slimy product was poured inito excess of water; the nucleo-albumin rises in strings to the top, the globulins sink to the bottom with the portions of unaffected tissue. This method he had previously used in the preparation of nucleo-albumins from lymph cells and from the thymus gland. (b) The finely divided orgaln is extracted with distilled water; from the aqueous extract a precipitate is obtained on the addition of a little acetic acid. This precipitate is Wooldridge's 'tissue-fibrinogetn' and is a mixture of nucleo-albumin, mucin, and lecithin. The mucin is only present in traces and is no doubt derived from the interstitial connective tissue; the lecithin is easily removable by alcohol at 400 C.; the chief constituent is nucleoc.

2 xii PROCEEDINGS OF THE PHYSIOLOGICAL albumin. Lymph glands, thymus, testis, brain, kidney and liver all yield a similar product. The proteid obtained is however not identical in all cases, differing in the percentage of phosphorus that it contains, and also in certain physical properties; thus the first method (a) just described does not yield any nucleo-albumin when liver and brain are the tissues under investigation; and the liver it may be stated yields a very small precipitate when treated by the second method. In the brain, the precipitate obtained from grey matter is much more abundant than from the white matter. The kidney yields a nucleo-albumin by both methods, and the product is the same whichever method is adopted; for after extraction of the nucleo-albumin by either method, traces only can be obtained if the residue is treated by the other: moreover phosphorus determinations give the same result (0 3 per cent.) in both cases. Wooldridge showed that intravascular coagulation was produced by intravenous injection of 'tissue fibrinogen.' Wright has found in addition that peptonuria is produced. While not denying the possibility that the 'peptone' originates from the foreign proteid introduced into the circulation, Dr H. found that the freshly prepared nucleoalbumin does not give the biuret reaction, nor does it give the nitric acid reaction characteristic of the proteoses. With copper sulphate and caustic potash, a violet not a pink colour is the result Nitric acid added to a solution of nucleo-albumin in weak sodium carbonate solution gives a precipitate, which partially clears up on heating, but there is no increase in the amount of precipitate on cooling. By suspending the nucleo-albumins in distilled water, it was found that in all cases they were coagulated by a temperature of about 600 C. The method of phosphorus determination adopted was briefly as follows: the material was washed thoroughly with dilute acetic acid, distilled water, cold and hot alcohol, and ether. Treatment with alcohol washes away the lecithin, and renders the remaining proteid insoluble. It was then washed with water faintly acidulated with hydrochloric acid to get rid of inoroanic phosphates; then with water, and finally dried and powdered. A weighed quantity was dissolved in boiling nitric acid and the solution concentrated on the water-bath, oxidation being completed by the addition of a little sulphuric acid and potassium chlorate. The phosphoric acid so formed was then precipitated by nitromolybdate of amnmonia; the yellow precipitate was collected, washed, and then redissolved in ammonia; and to this solution magnesium mixture added. The precipitated ammonio-mag-

3 SOCIETY, MARCH 12, nesium phosphate was collected on a filter of known ash, washed with dilute ammonia, and incinerated; the ash (magnesium pyrophosphate) was weighed, and from it the amount of phosphorus in the nucleoalbumin calculated. Mr PEYTON J. B. BEALE made a preliminary communication on the "Distribution of nerves in Synovial Meembranes." The method of preparing tissues for the examination and demonstration of the finest nerve fibres only was described. The method is a modification of that described by Dr Lionel Beale many years ago. The animal whose tissues are to be examined is killed preferably by shock. The aorta is then exposed and a small cannula secured in it; then a glycerine solution of osmic acid is injected for 5 minutes by means of a small syringe, the solution consisting of 1 /o solution of osmic acid-1 part glycerine-2 parts water -7 parts. A little weak glycerine is then injected and then Beale's carmine fluid. The injection of this fluid occupying about 20 minutes, the animal is then left in a warm moist chamber for 24 hours. After that time has elapsed, a little pure glycerine is injected and then Beale's Prussian blue fluid is injected. The tissues to be examined are then dissected out and washed in equal parts of glycerine and water to wash away excess of carmine fluid, and then in pure glycerine; finally they are left soaking in pure glycerine to which a few drops of glacial acetic acid and a few crystals of chromic acid have been added, the tissue is then teased out and examined with a high power. All the nuclei are stained with carmine and the capillaries are found injected with the Prussian blue. The specimens have to be washed many times in pure glycerine before being permanently mounted. In the case of larger animals, one limb can be injected from its principal artery, and subsequently treated as before described. A white animal should be selected so as to get the preparation quite free from pigment cells. Some specimens of synovial membrane from the knee-joint of the white mouse and rabbit were exhibited, showing the Villi, also some of human synovial membrane, stained by injecting the carmine fluid into the cavity of the knee-joint. *..

4 xiv PROCEEDINGS OF THE PHYSIOLOGICAL It was proposed to demonstrate and describe the actual distribution of nerves to the Synovial Membrane at a subsequent meeting of the Society. Mr R. T. HEWLETT described somiie experiments lie had performed to endeavouir to elucidate the question as to whether suclh a substance as lacto-globuilin exists'. He found that after saturating inilk witlh sodium chloride, further saturation with magnesium sulphate gave a precipitate, and that the same occurred on using the salts in the reverse order. This precipitate after being dissolved is precipitated by dialysis. It was also found that a solution of lact-albumin (prepared by saturating with ammonitlm sulphate the final filtrate after saturation with the two salts miientionied) is precipitable to a certain extent by dialysis. The so-called lacto-globulini seems to be a small quantity of caseinogen which resists precipitation on saturation with a single neutral salt; like caseinogen it is not coagulated by heat, it is precipitated by saturation with neutral salts and by acetic acid, and clots with rennet. Mr Hewlett also communicated some experiments on the effect of dilution on the temiiperature of coagulation of solutions of white of egg. In his experiments he used an oil-bath instead of the water-bath. He finds that dilution does not affect the coagulation-temperature nearly so mluch as stated by Haycraft and Duggan'. Up to a dilution of one in eight or niine the effect is inappreciable and beyond this the rise in the coagulation-temperature is niot so great as found by Haycraft and Duggan. Other experiments show that the phenomena of fractional heat-coagulation cannot be explained on the principle of dilution, and some of the results obtained seem to indicate that the conclusions of C orin and Berard are correct, viz. that white of eg,g consists of several proteids'. Mr R. A. YOUNG showed specimens of gelatin prepared from the retiform tissue of the intestinal mucous membrane, and also from lymphatic glands stripped of their capsules. In some quantitative experiments on dog's mucosa the percentage of gelatin varied from These results are opposed to those of Mall, who stated that gelatin could not be obtained from retiform tissue and regarded it as made tup of fibres differing, from ordinary white fibres. See Halliburton, Jouirnt. of Phys., Vol. xi. p. 449, and Sebelien, ibid. xii. p Brit. Mled. Journ. 1890, x. p. 167, and Proc. Roy. Soc. Edin., , p. 3U1. 3 Bul. Acad. roy. de Beig., xv

5 SOCIETY, MARCH 12, xv Mr T. G. BRODIE showed anl apparatus for obtaining the curve of elasticity of any tissue. The recording apparatus consists of a system of levers by means of which the curve obtained is not complicated by having to take into account the fact that the writing point describes an arc of a circle as in ordinary formis of apparatus. Increase and decrease in the tension on tlje tissue is affected through the elongation and relaxation of a hard iron spring, the upper end of which is supported on] the lower of three small pulleys (arranged according to the first systemn of pulleys), the free end of the cord round the upper pulley being attached to the tissue experimiiented upon. The object of the pulleys is to so diminish the movement of the upper end of thie spring that it may for the purpose of the experiment be considered fixed. The recording surface is driven by the same clockwork which extends and relaxes the spring, so that any irregularity in the movement of the spring produces a proportional alteration in the nmovement of the surface, and so the form of the curve is unaffected.