482 



NATURE 



[September 15, 1898 



Record of the aortic pressure is at the same time taken. After 

 ten minutes or so the pressure begins to steadily fall, the 

 respiratory pump, at first more active, gradually ceases, the 

 animal passes into syncope, the heart is almost empty and 

 death imminent. Compression of the abdomen will at this 

 point immediately restore the circulation and remove the con- 

 dition of syncope. The same end can equally well be attained 

 if the body of the animal be sunk in a bath of water. In the 

 wild rabbit, cat, dog, monkey and man, the power to resist the 

 influence of gravity on the circulation is very perfect. The 

 hutch rabbit is likewise restored by a bath, and in this fact 

 it is possible to find a simple explanation of the beneficial influ- 

 ence of baths on the bodies of debilitated men. The hydro- 

 static pressure of the water not only acts on the blood vessels, 

 but also causes the abdominal organs to float upwards. Thereby 

 the diaphragm is raised, and the tension on the vena cava 

 inferior relieved, that is to say, so soon as the dragging weight 

 of the abdominal organs be removed. 



Prof. Townsend Porter (Harvard, Boston, U.S.A.) com- 

 municated two important papers on the mammalian heart, 

 entitled " The nutrition of the heart through the vessels of 

 Thebesius," and ' ' The beat of the isolated mammalian ven- 

 tricle fed on blood-serum alone." His method was demonstrated 

 and consists in the revivifying of the excised and washed out 

 dog's heart by simply allowing a stream of defibrinated dog's 

 blood to flow through it from the coronary artery. 



A heart fed simply through the veins of Thebesius and the 

 coronary veins will maintain strong, rhythmic contractions for 

 many hours if supplied with oxygen at high tension. The 

 absence of corpuscles was readily borne by the heart. Con- 

 tinued rhythmic contractions were obtained with the serum 

 alone, so soon as the oxygen tension rose to about two atmo- 

 spheres. It follows that the mammalian heart fed through the 

 vessels of Thebesius and the coronary veins with blood-serum 

 alone will maintain rhythmical contractions for hours when 

 surrounded by oxygen at high tension. Isolated pieces of the 

 ventricle beat if fed with serum through a branch of the 

 coronary artery. 



These experiments permit the conclusion that even isolated 

 portions of the mammalian ventricle supplied through their 

 nutrient arteries with a small quantity of serum at very low 

 pressure will maintain rhythmical, long-continued, forceful con- 

 tractions when surrounded by oxygen at high tension. 



The influence of salts upon the electromobility of medullated 

 nerve was the subject of a communication, illustrated by experi- 

 ments and by lantern galvanograms, by Prof. A. D. Waller, 

 F.R.S. (London). The method of investigation was that 

 previously employed by the author. 



Excised frog's sciatic laid across unipolar electrodes in moist 

 chamber. Electrical response to electrical excitation at regular 

 intervals photographically recorded before and after modification 

 of the nerve by various salts dissolved in normal saline. 



In the action upon nerve of a salt BA, the predominant moiety 

 is B (the basic or electropositive element), e.g. any potassium 

 salt is more eff"ective than any sodium salt. 



The acidic or electronegative element A is of subordinate 

 action, e.g. KI> KBr. 



+ - + - 



Is the action upon nerve of a salt B A, or of an acid H A, 

 + - 

 or of an alkali B OH, that of dissociated ions ? 



Do e.g. HNO3 act upon nerve by virtue of its electropositive 

 H, and KOH by virtue of its electronegative OH? 



Certainly not exclusively. Because e.£. the action of the 

 highly dissociated w/ioHNOj is not greater than that of the 

 slightly dissociated CH3, CO'OH, and the action of KOH is 

 considerably greater than that of NaOH at equality of dilution 

 and of dissociation. The action of the highly dissociated 

 chlorides, bromides, &c., is not greater than that of the slightly 

 dissociated acetates. 



NO. 1507, VOL. 58] 



Strength of solution 



^ ' ~ V Effect upon 



% ^f. -A^. electrical response. 



0*490 w/20 «/io Abolition in 7 mins. 



0-630 w/io m/io Abolition in 1 5 mins. 



o'6oo ot/io «/io Abolition in 15 mins. 



0'653 w/15 »IS Abolition in 25 mins. 



0*450 w/20 «/20 Abolition in 15 mins. 



0*200 ml 20 «/20 Diminution. 



0*140 ml^o «/40 Abolition in 8 mins. 



H3SO4 



HNO3 



CH3, COOH 



H3PO4 



CH3, CHOH, COOH 



NaOH 



KOH 



Prof. E. Wertheimer (Lille) demonstrated observations, made 

 with M. Lepage, that the influence of the accelerator nerves oni 

 the heart is much less, in the dog, during expiration than during, 

 inspiration. 



Prof. Griitzner (Tubingen) demonstrated (l) a tambour by 

 means of which the slightest alteration in the pitch of a sung, 

 note can be visually demonstrated before an auditorium ; (2) a 

 method of analysis of a compound note by means of interference 

 established by stopped tubes of different lengths ; (3) his graphic 

 record of induction currents upon paper. 



Dr. J. N. Langley, F.R.S. (Cambridge), demonstrated his- 

 discovery of the possibility of obtaining an experimental union 

 between the nerve-fibres of the vagus nerve and the sympathetic 

 nerve-cells of the superior cervical ganglia. The vagus and 

 sympathetic nerves were ligatured with horse-hair. On August 

 23 sixty-four days had elapsed since the end of the vagus- 

 was joined to the sympathetic nerve. The vagus nerve was 

 then cut near the skull, and its peripheral end stimulated. 

 Regeneration had taken place ; the stimulation of the vagus- 

 caused opening of the eye, retraction of the nictitating mem- 

 brane, dilation of the pupil, contraction of the vessels of the 

 ear, and more or less of the other effects ordinarily produced by 



stimulating the cervical sympathetic. The injection of 20- 

 milligrams of nicotin temporarily prevented the vagus from 

 producing any of these effects, but did not prevent stimulatiork 

 of the superior cervical ganglion from producing them. This- 

 result shows in the clearest manner that the specific effect of the 

 excitation depends upon the specific character of the peripheral 

 ending, not on the character of the central conducting paths. 



Prof. Heymans (Ghent), gave experiments upon physiological 

 and artificial disintoxication. The simple nitrils are within the 

 organism decomposed and eliminated in the form of sulpho- 

 cyanide. This physiological disintoxication, acting under the 

 intervention of sulphuretted organic bodies, is much increased 

 by the administration of certain compounds of sulphur such as- 

 the hyposulphites, &c. These sulphur compounds prevent or 

 remove the poisonous effects of a dose of the nitrils many times 

 that sufficient to kill. 



Prof. Sherrington, F.R.S. (Liverpool), demonstrated his dis- 

 covery of inhibition of the tonus of a skeletal muscle by the 

 excitation, either electrical or mechanical, of the antagonist 

 muscle. The phenomena has bearing upon spinal coordination 

 for volitional and other kinds of movement. The experiment 

 shown dealt with the antagonistic flexors and extensors of the 

 knee-joint. The stretching of a muscle produced by the con- 

 traction of its antagonist may excite (mechanically) the sensorial 

 organs in the muscle that is under extension ; in this way a 

 reflex of pure muscular initiation may be started. The ex- 

 periment proved that electrical excitation of the central end 

 of an exclusively muscular nerve produces inhibition of its 

 antagonist, (i) The central end of the severed hamstring 

 nerve was faradised. This nerve contains sensory nerve-fibres 

 from the flexor muscles of the knee. The effect of these on the 

 extensor muscles of the knee was seen (a) in elongation of those 

 muscles, (S) in temporary diminution of the knee-jerk. (2) The 

 exposed flexor muscles detached from the knee, and therefore 

 incapable of mechanically affecting the position of the joint, 

 were then stretched or kneaded. This produced reflex elong- 

 ation of the extensor muscles of the knee and a temporary 

 diminution of the knee-jerk. It may therefore be that reciprocal 

 innervation, which Prof. Sherrington has pointed out to be 

 a common form of coordination of antagonistic muscles, is 

 secured by a simple reflex mechanism, important in its execution 

 being the tendency for a muscle to produce its own inhibition 

 reflexly by mechanical stimulation of the sensory apparatus in 

 its antagonist. 



Prof. O. Frank (Munich) demonstrated methods of recording 

 the action of the cardiac muscle both isotomically and iso- 

 metrically. 



