64 



NA TURE 



[November 21, 1901 



which has exlraordinary tryptic but no amylolytic power; but 

 the amylolytic power of the juice remains in the juice after 

 removal of the tryptic proteitl. 



Dr. O. Cohnheim (Heidelberg) reported experiments on the 

 disappearance of peptones placed under the influence of the 

 intestinal mucosa. The peptones were not changed to albumin, 

 but were split up into crystalloid cleavage products. This 

 cleavage was accomplished by a ferment ercpsiii produced by the 

 inlesline, and active on peptone but not on albumin. 



Drs. Delezcnne and Drouin (Paris) had invesligaleil the ques- 

 tion of the origin of the pepsin which is secreted in urine. They 

 found that that pepsin might have either or both of two sources, a, 

 the pepsin secreted by the stomach and presumably reabsorbed, 

 3, the pepsin known to exist in the muscles, salivary and other 

 glands and organs. The authors demonstrated that the urinary 

 pepsin had its origin in the gastric pepsin, and was obtained by 

 reabsorption of that pepsin from the stomach itself. (l) In the 

 dog after removal of the stomach, never under any condition of 

 nutrition or in any digestive period is any proteolytic ferment 

 whatever detectable in the urine. (2) In the dog after 

 establishment of a gastric fistula and the prevention of the 

 entrance of gastric juice into the intestine, the urine, as usual, 

 contains pepsin. (3) In the dog after exsection of the 

 stomach, the introduction of gastric juice into the intestine 

 fails to result in the appearance of pepsin in the urine. 



Dr. Drouin (Paris) had made observations to test the part 

 played by the spleen (Schiff, Herzen) in pancreatic digestion. 

 He had, in the dog, united the oesophagus to the duodenum and 

 converted the stomach into an independent cr^/rft'-jai' opening on 

 the surface by a fistula. Thus he eliminated gastric digestion 

 altogether and left pancreatic action the chief rolt in digestion. 

 He had then excised the spleen. The excision produced no 

 appreciable difference in the assimilative powers, digestive 

 activity or general well-being of the animal. The removal of 

 the spleen seemed, further, in no way to alter the quality or 

 quantity of the juice secreted by the fistulous stomach. 



Prof. Gley (Paris) gave a r^siiiiu' oi his experiments and con- 

 clusions regarding the rfile and mutual interdependence of the 

 thyroid and the parathyroid glands. The evidence was both 

 cherr.ical and histological. He regarded the parathyroids as 

 complemental in function and structure to the main thyroid. 

 He referred to the work done recently by Mr. Walter Edmunds 

 (London), and a fuller summary of his communication can be 

 found in an admirable article published by Prof. Gley recently 

 in the English medical journals. 



Prof. V. Ducceschi (Rome) communicated researches deal- 

 ing with aromatic groups in the proteid molecule. Cinnamic 

 acid could be obtained from egg-albumin and serum-albumin 

 by a method which did not in that way split up tyrosih. 

 It came probably from the aromatic group whence proceed in 

 the putrefaction of some proteids phenylacetic and phenylpro- 

 pionic acids ; probably that group is phenyl-o-amidopropionic 

 acid. From 500 grn*. of egg-albumin, 2 grm. of /3-phenylacrylic 

 acid (cinnamic acid) are obtained. 



Among other communications given in this section were 

 those dealing with the speed of absorption and of elimination of 

 acetylene gas by the organism (Prof. Ugolino Motso, Genoa\ 

 the presence of lower bomologues of caffeine and theobromine 

 in certain plants (Prof. Albanese, Pavia), the pharmacodynamic 

 action of acet)l chloride (Prof Spineanu, Bucharest), the forma- 

 tion of fat in the animal body (Prof. Boruttau, Giittingen), 

 the diastatic action of human saliva (Dr. Oehl, Pavia), the 

 osmotic tension of milk, urine and amniotic fluid (Drs. Vicarelli 

 and Cappori, Turin), electromotive changes observed in .solu- 

 tions of oxalic acid under exposure to light (Dr. <^)uerton, 

 Brussels), the fatty components in lecithin (Dr. Ilenriquez, 

 Copenhagen), the influence of intestinal absorption on the 

 diurnal curve of output of urea (Dr. Slosse, Brussels), the 

 microchemistry of the cell (Dr. R. Kohn, Prague), a method 

 for determination of the acidity of the gastric juice (Levi and 

 I. illi, Modena), hxmolysmometry (Dr. E. Buffa, Turin). 



LIcctrophysiology was represented, as regards special com- 

 munications to the meetings of the Congress, chiefly by the 

 papers of Profs. Borutlan, Fano, Herzen, Mislawski, Waller, 

 Wedenskii and Weiss. The first named (Gottingen) demonstrated 

 capillary-electrometer photograms of the action current of the 

 frog's nerve obtained daring strychnine tetanus. The frequency 

 of the rhythm w.as about eight times per second, and the relative 

 slowness of the curve was explicable by the imperfect syn- 

 chronism of the course of the individual waves. Prof Boruttan 



NO. 1673, VOL. 65] 



could not accept Sir J. B. Sanderson's suggested explanation of 

 these strychnine oscillations of the electrometer line, and pro- 

 posed to call them pseuilotetanic. He finally entered upon the 

 question of the proper functional rhythm of the nerve-cell. 



Prof. Herzen (Lausanne) dealt with the separation of the 

 action-current of nerve from the functional " impulse " of nerve. 

 He appealed to, among other data, that of Boruttan's strychnine 

 experiment, in which, from a partially dried nerve trunk in- 

 capable of transmitting the impulses from the strychnised 

 centres to the limb-muscles, the transmission of the action- 

 current was still demonstrably obtainable. 



Dr. Waller (London) gave in two complemental reports a 

 well-illustrated demonstrational rt'sumj of the more recent of 

 his work on the electric response of living matter, both plant 

 and animal, to general and to adequate stimuli. New points 

 were added to those already familiar to English students of the 

 question. A comprehensive search has been undertaken into 

 the distributional width of the existence of this " reaction of 

 vitality " which he regards as coextensive with life itself. 



Among points established by him were the following : — 

 Mechanical excitation of a petiole renders the excited part 

 electropositive to the unexcited. The illuminated part of a leaf 

 is electropositive to an unilluminated. Electric .stimulation of 

 uninjured vegetable tissues is followed by an electrical response 

 which is abolished at high and low temperatures, by anesthetic 

 vapours, and in consequence of strong electric excitation. 

 A general relation between magnitude of response and " vitality " 

 of plant or plant organ is noticeable, the stronger the " vitality " 

 the greater the voltage of the response. This in seeds is con- 

 firmed V)y subsequent germination. Plant tissues when submitted 

 to stimulation of uniform magnitude at regular intervals exhibit 

 the characteristic changes known in animal physiology as 

 "peripheral fatigue " and " recovery," " staircase effect " and 

 summation. In consequence of one or more strong induction 

 currents, the electrical conductivity of living plant tissues is 

 greatly augmented. Among his observations upon animal 

 tissues may be cited the following. The skin of the cat's foot 

 gives an electrical response to excitation of the .sciatic nerve; 

 this current is ingoing, it has a latent period of about three 

 seconds and an E. .M.F. of a hundredth of a volt. In the skin 

 of the frog's foot it can be shown that atropin abolishes this 

 indirect response to excitation of the nerve. The electrical 

 response of healthy excised human skin to electrical excitation 

 of both directions is outgoing. Human skin continues to 

 exhibit the outgoing response characteristic of the living state 

 for I -10 days after excision. Immersion in hot water at once 

 destroys irrecoverably the power of the skin to respond. The 

 electrical response of the skin and of the eyeball to direct 

 excitation is comparable with similar effects witnessed in electrical 

 organs. 



Dr. Weiss (Paris) showed that if two successive electric 

 stimuli be applied to a nerve at the same point of the nerve, the 

 direction of the electric currents applied is important in 

 determining the summation of the stimuli. If the electric 

 stimuli are both of the same direction and occur within the 

 duration of the latent period, the effect of the one is demon- 

 strably .idded to the eflect of the other. If they are, however, 

 of opposite direction the stronger of the two is alone effective, 

 at least if the weaker is subliminal it produces no obvious 

 effect. That is, if the stronger of the stimuli is of just liminal 

 value it remains of just liminal value whether preceded 

 or followed by the weaker of opposite direction. The addition 

 to it of the weaker in nowise changes the result produced by the 

 stronger on the nerve. 



Prof. Wedenski (St. Petersburg) drew attention to obser- 

 vations, conducted in his Laboratory, indicating the fundamental 

 similarity of inhibition of nerve to narcosis of nerve. He 

 maintained that all general excitants of nerve exhibit three 

 successive phases of influence upon nerve — a phase in which the 

 rhythm of the excitation exhibits modification in the rhythm 

 of the response, a phase in which there is a depression of con- 

 ductivity of the excited state, a phase of depression of all 

 resp nse to excitation. 



Prof. Vitzou (Bucharest) gave an account of experiments 

 instituted to test the supposed inexcitability of the grey matter 

 of the spinal cord to artificial stimuli. He claimed that his ex- 

 periments demonstrate that the spinal grey matter, like the 4 

 cerebral grey matter, is excitable by faradic currents. 



Prof. Mislawski (Kasan) gave a communication upon the 

 negative variation of reflex action. Du Bois Reymond's discovery 



