692 



PHYSIOLOGY. 



due not to increased frequency of the con- 

 tractions, but to their great prolongation, a 

 second contraction beginning before its prede- 

 cessor is finished. 



Blood and the white of egg in small quantities 

 obviate the changes which occur with saline 

 solution; so also does potassium chloride, in 

 much smaller quantities than exist in serum. 

 Phosphate of potash in smaller proportions 

 than exist in the blood counteracts the pro- 

 longed relaxation which the solution occasions ; 

 and in general, from the tenor of Dr. Ringer's 

 experiments with other compounds of that 

 metal, probably any potassium salt contributes 

 to such an effect. This is not the case with 

 phosphate of soda, and it is hence inferred that 

 the effect with potassium phosphate is due to 

 the potassium, and not to the phosphoric acid. 

 Serum albumen, free from potassium salts, has 

 no effect upon the dilatation produced by the 

 saline solution. 



Distilled water, when introduced to the ven- 

 tricle, throws it into complete and permanent 

 systole, affecting the cardiac as it does the 

 skeletal muscles, and inducing water rigor. 

 This effect is renewed by adding sodium chlo- 

 ride to the water, while white of egg dissolved 

 in water affects the ventricle just as the water 

 does. Blood, however, is more efficient in 

 restoring the contractions than simple saline 

 solution ; but if the rigor, which is in the be- 

 ginning a condition closely similar to rigor 

 mortis, is continued too long, it becomes a true 

 rigor mortis, when the ventricle turns white 

 and opaque, and neither sodium chloride nor 

 blood mixture will cause a resumption of con- 

 tractility. Phosphate of soda removes water 

 rigor, chloride of potassium does not, either in 

 physiological or toxic doses. 



The saline solutions used in the preceding 

 experiments were made with the ordinary wa- 

 ter of the New River Water Company, and 

 their effects were probably promoted by the 

 impurities in that water. When distilled water 

 was used for the solution the effects were dif- 

 ferent. An addition of one part of a 1 per 

 cent solution of potassium chloride solution to 

 one hundred parts of circulating saline formed 

 an excellent artificial circulating fluid for the 

 heart. Calcium and calcium compounds, even 

 in minute doses, produced the formerly de- 

 scribed changes in the ventricular beat, and 

 their action seems to be favored by cold. Add- 

 ed to the saline solution, with potassium chlo- 

 ride, they make a good artificial circulating 

 liquid. As this composition is neutral, the 

 conclusion is drawn that alkalinity of the circu- 

 lating fluid is not necessary for contractility. 

 The alkaline reaction of the blood is, however, 

 no doubt necessary, indirectly, to contractil- 

 ity, for muscular contractions develop acidity, 

 which would give an acid reaction to a neutral 

 fluid, while the heart can not contract when 

 supplied with a circulating fluid of that char- 

 acter. Sodium bicarbonate added to saline 

 solution prolongs slightly better contraction 



and dilatation. All of its effects are obviated 

 by a physiological quantity of potassium chlo- 

 ride. 



A mixture containing a hundred parts of 

 saline solution, five of sodium bicarbonate, five 

 of calcium chloride solution, and one of potas- 

 sium chloride, makes a circulating fluid with 

 which the heart will continue to beat perfectly. 

 The heart's contractility, however, can not be 

 sustained by any combination of these solutions 

 without the calcium salt ; but the addition of 

 a lime salt to any of the combinations will 

 sustain contractility, and will restore it after 

 it has ceased. It is therefore concluded that a 

 lime salt is necessary for the maintenance of 

 muscular contractility. Yet, while calcium salts 

 are necessary for the proper contraction of the 

 heart, if they are not antagonized by potassium 

 salts the beats would become so broad and the 

 diastolic dilatation so prolonged that much fu- 

 sion of the beats would occur, and the ven- 

 tricle would be thrown into a state of tetanus. 

 Since the ventricle will continue to beat per- 

 fectly for hours without any sodium bicarbon- 

 ate, it is evident that the normal trace is the 

 result of the antagonizing action of calcium 

 and potassium salts. 



PEINCIPAL PHYSIOLOGICAL PUBLICATIONS AKT> 

 MEMOIES OF THE YEAE. The literary work of 

 the year in physiology includes a third edition 

 of Professor Mapother's work, revised by Dr. 

 Knott ; a seventh edition of Dr. Dalton's work 

 in a form which, while it is less voluminous 

 than the previous editions, is none the less 

 clear and precise ; and a second edition of Har- 

 ris & Power's " Manual for the Physiological 

 Laboratory." In periodicals have appeared re- 

 searches on "Chlorophyll," by Pringsheim and 

 Lankester; articles on the "Lymphatic Sys- 

 tem," by Klein, and on " Saprolegnia in rela- 

 tion to the Salmon Disease," by Walpole and 

 Huxley; and "Notes on Echinoderm Mor- 

 phology," by Herbert Carpenter, in the " Quar- 

 terly Journal of Microscopical Science " ; a dis- 

 cussion of " The Segmental Value of the Cra- 

 nial Nerves," by Dr. Milnes Marshall, and a 

 description of the " Cerebral Sinuses and their 

 Variations," by Mr. J. F. Knott, in the "Jour- 

 nal of Anatomy and Physiology " ; and papers 

 by Martin and Sedgwick on " The Mean 

 Pressure and the Characters of the Pulse Wave 

 in the Coronal Arteries of the Heart," and by 

 C. S. Roy on " Rhythmical Contractions of the 

 Spleen Independent of Cardiac Movements," 

 in the " Journal of Physiology." 



In Continental literature, Georges Hayem's 

 " Lecons sur les Modifications du Sang " give 

 the results of careful investigations of the 

 changes presented by the blood under the in- 

 fluence of various remedies and therapeutic 

 agents. Malassez has specially discussed the 

 development of the red corpuscles in the me- 

 dulla of the bones, and Marjet the spontane- 

 ous changes undergone by the colored corpus- 

 cles preserved in plasma without access of air. 

 Alexander Schmidt has given in Brown-S6- 



