November 4» '^97J 



NATURE 



'9 



the quantity of blood flowing through in a unit of time, the 

 arterial pressure, and the coefficient of viscosity be known, it is 

 easy by Poiseuille's law to calculate the bore and length of a 

 tube through which, under given conditions, the same quantity 

 <if blood would flow. The aim of the experiments is to measure 

 and express the resistance through the several regions and 

 organs of the body in this manner. 



Prof. A. R. Cushny described rhythmic variations in the 

 strength of the contractions of the mammalian ventricle under 

 the action of certain drugs of the digitalis groups. The 

 variations occur only when the ventricle is beating at a 

 rate different from that of the auricle. If the conjunc- 

 tion of the auricular with the ventricular beat fall at 

 a favourable time, the beat of the ventricle is strong ; 

 if at an unfavourable, is weak. The systole of the auricles 

 at a certain stage of the rhythm falls at the systole of the ven- 

 tricle : the auricle in consequence cannot empty itself. It was 

 also pointed out that the action of nicotin on the mammalian 

 heart is exactly similar to its action as discovered by Langley on 

 the ganglia of the sympathetic system. 



Prof. Loeb demonstrated experiments on the influence of the 

 discharge of highly-charged conductors on nerve-muscle prepara- 

 tions. It was known that if a highly-charged conductor be dis- 

 charged in the neighbourhood of a nerve, the muscle contracts. 

 He found in relation to this the following new facts, (i) If the 

 nerve be placed parallel with the spark discharge of a friction 

 machine, maximal effects are obtained when the electrodes 

 are symmetrical in regard to the nerve. If the nerve 

 be set to one side near one electrode the effects decrease. 

 (2) If the nerve be set at right angles with the spark 

 discharge, minimal effects are obtained when the electrodes 

 are symmetrical to the nerve. Strong effects are obtained 

 by placing the nerve near one electrode. (3) By putting 

 a conductor behind the nerve in Case i, the effects are 

 effaced or diminished. By putting a conductor between the 

 nerve-muscle preparation and one electrode in Case 2, an increase 

 in effect is produced. It had been shown in the last ten years 

 that the phenomena of heliotropism, long observed in plants 

 alone, are common in the animal kingdom. In both cases the 

 effects of the light are determined by the direction of the rays 

 and the length of waves, the more refractive of the visible 

 spectrum teing chiefly effective. It is possible to directly 

 stimulate nerve by electric rays. Apparently the galvanic current 

 iloes not directly act on living matter; its effects as stimulus 

 being in reality only due to the direct or secondary products of 

 electrolysis. 



Prof. Waller gave a demonstration and description of the 

 action of various reagents upon the electrotonic currents of 

 nerve. He has succeeded in completely proving that these 

 currents are in the strictest sense physiological, and they 

 therefore become more than ever of high physiological 

 interest. In the frog's nerve the anelectrotonic current 

 considerably exceeds the katelectrotonic in magnitude. The 

 action of acids, of alkalis, of carbonic acid, of some anes- 

 thetics, and also of tetanisation and of variations of tempera- 

 ture were all dealt with in their liearing upon the ratio and 

 magnitude of the electrotonic currents. Slight acidification 

 diminishes the anelectrotonic current and increases the kat- 

 electrotonic : treatment with bases diminishes in a typical 

 manner the katelectrotonic current. The effect of prolonged 

 tetanisation upon the katelectrotonic current is similar to that 

 of acidifidation. Its effect, though less uniform on the an- 

 electrotonic current, yet strongly resembles the effect produced 

 by carbonic acid. Prof. Waller, indeed, holds that his experi- 

 ments bring strong evidence that the tetanisation of nerve 

 induces in the nerve the production of CO2 to a thus detectible 

 extent. Electrotonic currents are diminished for a time by 

 exhibition of ether vapour, and are rapidly and permanently 

 abolished by weaker percentages of chloroform vapour. In 

 other words, chloroform rapidly kills the nerve outright, while 

 by ether it is easy to merely diminish or abolish the excitability 

 of the nerve for a temporary period. 



Dr. Mackay communicated a paper on the absorption of 

 " ferratin" and of hemoglobin by the intestinal wall. He had 

 used the microchemical tests for iron devised by Prof. Mac- 

 allum. He found that the iron of ferratin is absorbed by the 

 epithelial cells of the villi, and that it was passed inwards to 

 the leucocytes. Deposits of iron could further be found in the 

 liver, spleen, and lymph glands. The iron of hemoglobin is 

 absorbed by the epithelial cells as a compound, probably 



NO 1462. VOL. 57] 



hxmatin. In this case deposits are also found in the organs of 

 the portal system, and there is indication of some excretion of 

 iron in the bile and in the urine. 



Dr. Noel Paton read a paper on the phosphorus metabolism 

 of the salmon in fresh water. Sample salmon were throughout 

 the spring, summer and autumn taken from the mouths of 

 certain rivers, and others from the upper waters of the same 

 rivers. Abundant observations clearly show that the fish do not 

 feed during their stay in fresh water. The muscle substance 

 steadily diminishes, while the ovaries and testes grow at its ex- 

 pense. The fats and proteids lost from the muscles are sufficient 

 to supply these materials for the growing genitalia, and to yield 

 a very large amount of energy for muscular work. The question 

 here discussed is the exchange of phosphorus. It is first shown 

 that in muscle the phosphorus is chiefly in the form of inorganic 

 phosphates, though a comparatively large amount of lecithin 

 and a small amount of nuclein are also present. In the ovary 

 the phosphorus is chiefly combined in the pseudo-nuclein-— 

 ichthulin ; but it is also present in considerable amounts in 

 lecithin, and in very small amounts as inorganic phosphates. In 

 the testis the phosphorus is chiefly in the form of true nucleins, 

 but there are also a considerable quantity of lecithin and a 

 small quantity of inorganic phosphate. As the season advances 

 the phosphorus in the genitalia increases, while the phosphorus 

 of the muscle diminishes. The loss of phosphorus from the 

 muscle is barely sufficient to account for the gain in the ovary, 

 amply sufficient to yield the increase of phosphorus in the testis. 

 The lecithin lost from the muscle is sufficient only to account 

 for a small part of the lecithin gained by the ovary. The 

 lecithin and ichthulin of the ovary must thus be found by 

 synthesis'as these structures grow. The nuclein of the testis 

 must be formed in a similar manner. 



The presence of considerable amounts of lecithin in the 

 growing ovary and testis would seem to indicate that this 

 substance is one of the first stages in the construction of nucleo 

 compounds. 



Prof. W. P. Lombard gave a communication on the effect of 

 frequent excitations on the contractility of striped muscle. 

 When the muscle is made to give a series of contractions the 

 height of the contraction is seen to increase. The muscle 

 contracted very much higher to an induction shock just after 

 than just before a short period of tetanic excitations. Each of 

 a series of short tetani following each other in rapid succession 

 was, until fatigue appeared, higher than its predecessor. The 

 after effect of excitation is to increase the capacity of the muscle 

 to shorten. When the inertia of the writing lever is increased 

 each of a series of short tetani is seen to begin with a sudden 

 high rise, the throw of the lever carrying the curve above the 

 actual shortening of the muscle. The height of the introductory 

 peak exhibits in repeated tetani a staircase like growth, and this, 

 in spite of the total contraction being lessened by an increasing 

 growth of contracture heightening the base-line. The effect of 

 the repeated excitations is to cause a more and more sudden and 

 intense liberation of energy. 



Prof. Sherrington demonstrated the production of an intense 

 colour of subjective origin by whirling a disc coloured with red 

 on a black-white ground. The disc should contain a black 

 sector of about 1 70°. From one edge of the black sector broad 

 concentric vermilion arcs are carried into the peripheral while 

 part of the discs for about 90°; from the other edge of the disc 

 similar arcs in the central part of the white field. On rotating 

 the disc .so that black follows red in the circumferential field, and 

 precedes red in the central, the outer arcs appear a dull dark 

 maroon, the inner a bright orange, and the spaces between the 

 outer arcs appear deep blue-green, and the spaces between the 

 inner arcs appear primrose-yellow, especially when viewed by a 

 yellowish illumination. Prof. Sherrington offered an explana- 

 tion for the phenomenon which he based on negative after- 

 images heightened by simultaneous and successive contrast- 

 effects which, as he demonstrated at the meeting, take effect 

 even when speed of translation of a surface prevents the 

 mind from perceiving the space-relations of the distribution 

 of the contrasted tints. It was pointed out that the disc 

 is being used in this experiment similarly to a circular 

 rheotome for summation of effects which taken singly would by 

 reason of their small quantity be imperceptible. It was also 

 demonstrated that by whirling the disc at higher speed the 

 phenomenon becomes altered, the reds and greys then matching 

 over the whole surface of the disc, the greys assuming a pale 

 green tint ; when this is obtained, it was urged that one factor 



