722 



PHYSIOLOGY. 



dominantly directed to the first two factors, 

 while the third has been left in comparative neg- 

 lect. In entering upon its study, Sydney Ring- 

 er and Harrington Sairisbury find a similarity 

 between the act of muscular stiffening in rigor 

 mortis and the act of clotting of the blood. In 

 both there are the passage of a substance from 

 the liquid to the solid state, with evolution of 

 heat, the development of an acid, and the ap- 

 pearance of carbonic acid. From this comparison 

 the passage is direct to a comparison between 

 the contraction of muscular fiber and the act of 

 clotting of the blood. Experiments with contract- 

 ing muscles have shown that the presence of cer- 

 tain salts exerts a marked effect on the act of con- 

 traction ; and among salts those of lime are cata- 

 bolic in function, effecting a passage from high- 

 er to lower vitality, while those of potassium are 

 anabolic, or of an opposite character. The au- 

 thors inquired in their experiments whether a 

 similar relation of the salts obtained to the act 

 of clotting. Their conclusions are a confirma- 

 tion of the statement made by Green that calci- 

 um is an essential to the act of clotting ; ampli- 

 fication of his statement by the determination 

 that calcium chloride is a very efficient salt in 

 favoring clotting, and conclusion from experi- 

 ments of themselves and others that the effect 

 of calcium is a generic effect, belonging proba- 

 bly to all its salts ; determination that strontium 

 and barium act like calcium, but are less power- 

 ful ; suggestion that this action will be found to 

 appertain to the salts of strontium and barium 

 generally ; determination of the restraining action 

 of potassium and sodium salts the potassium 

 effect being less than the sodium effect ; and an- 

 tagonism of the salts of lime, strontium, and 

 barium on the one hand, and of potassium and 

 sodium on the other. 



An investigation of the cause of the first sound 

 of the heart by J. Berry Haycraft was directed 

 to the determination of the question of fact, 

 whether the resonance tones, or muscle sounds 

 which will undoubtedly accompany the contrac- 

 tion of the ventricle are accompanied by a true 

 valvular note as well. The author, who believes 

 his own ear to be tolerably good, availed himself 

 of the assistance of two other gentlemen, who 

 had musical attainments of a high order. The 

 conclusion drawn from the experiments is that 

 the first heart sound is an impure musical note, 

 a minor third below the second sound, and in 

 the bass clef. It is a valvular sound like the sec- 

 ond sound. It is accompanied by resonance tones 

 of the chest, stethoscope, and ear, which are pro- 

 duced by the shock of the contracting heart. It 

 is also possible that concomitant sounds are pro- 

 duced by the rushing of the blood and other 

 minor disturbances. 



Experiments by Sydney Ringer previously re- 

 ported upon have shown that heart contractility 

 in frogs is sustained by an adequate mixture of 

 calcium and potassium salts in saline solution ; 

 that while distilled water is by reason of its disin- 

 tegrating action on the exposed tissues destruct- 

 ive to fishes, the effect of sodium chloride, so- 

 dium bicarbonate, and potassium chloride added 

 singly is to cause life to be sustained much 

 longer ; that distilled water quickly disintegrates 

 the tissues of cilia, while sodium and calcium 

 salts prevent their disintegration; and that 



swelling of the fucoid laminaria in distilled wa- 

 ter is not lessened by the addition of sodium or 

 potassium salts, but is greatly controlled by the 

 addition of a minute quantity of a calcium salt. 

 The current substance binding the cells in both 

 animal and vegetable tissues appears to be sim- 

 ilarly affected by lime, which hinders their imbi- 

 bition of water and prevents swelling in the al- 

 gae and disintegration in the case of the fish. 

 Continuing his investigation, Dr. Ringer's latest 

 paper is on the influence of lime, sodium, and 

 potassium salts on the development of ova and 

 growth of tadpoles. Frog's spawn placed in 

 distilled water develops not at all, or but little,. 

 but undergoes a swelling of the mucilaginous- 

 envelope and a separation and enlargement of 

 the vitelline membrane. With chloride and ni- 

 trate of lime development proceeds further than 

 with distilled water, but not so far as with cal- 

 cium sulphate, while this, in its turn, is far infe- 

 rior to tribasic phosphate of lime. These results 

 correspond to the influence of lime salts on the 

 frog's heart. Tadpoles placed in distilled water 

 die in from twelve to eighteen hours, while the 

 epithelium separates in flakes. They likewise die 

 sooner in water containing bicarbonate of soda,, 

 lime water, calcium chloride, and sulphate of 

 lime ; while carbonate of lime and tribasic phos- 

 phate of lime sustain life for a considerable time. 

 The author invites attention to the interesting 

 fact brought out in his experiments that those 

 lime salts most efficacious in sustaining function 

 of cardiac tissue are those best adapted to sus- 

 tain life in ova and tadpoles. He also remarks 

 that it would appear that those salts of lime in 

 which the lime atom is least saturated by the 

 acid are the most capable of sustaining function. 



Investigations of the regulation of the blood 

 supply of the brain have been conducted by C, 

 S. Roy and C. S. Sherrington in experiments on 

 the stimulation of various nerves and the action 

 of a number of drugs. The principal general 

 conclusions drawn from the study are that the 

 blood supply of the brain varies directly with 

 the blood pressure in the systemic arteries ; that 

 when the vaso-con stricter centers are excited di- 

 rectly in the normal animal, by interference with 

 the nutrition of the brain and spinal cord, the 

 rise of the aortic blood pressure which results 

 is advantageous to the economy in that it in- 

 creases the blood supply of the central nerv- 

 ous system ; that the rise of arterial pressure, 

 which may result from certain centripetal nerve 

 impulses, is of benefit to the economy by increas- 

 ing the blood supply of the central nervous system, 

 which is called into increased functional activity 

 by the impulses in question, as well as by aiding 

 the congestion of the part of the body whence 

 the impulses are derived ; that there is no evi- 

 dence of the existence of vaso-motor nerves for 

 the brain outside of the cerebro-spinal canal ; 

 and that the chemical products of cerebral me- 

 tabolism contained in the lymph that bathes the 

 walls of the arterioles of the brain can cause va- 

 riations of the caliber of the cerebral vessels, and 

 that in this reaction the brain possesses an in- 

 trinsic mechanism by which its vascular supply 

 can be varied locally in correspondence with lo- 

 cal variations of functional activity. 



The view having been put forward by Fick 

 that the mode of action of the clotting ferments 



