PHYSIOLOGY. 



and biliverdin, in point of oxidation and of h yd ra- 

 tion. Those processes affecting the original funda- 

 mental pigment of the bile, bilirubin, begin possibly 

 in the hepatic cellules and in the biliary ducts, and 

 certainly go on in the gall bladder, but the artificial 

 conditions for this change are not here realized. 

 Hence the hypothesis of an agent or condition for 

 inducing oxidation (hepatic oxidasis). In the inver- 

 tebrates the authors distinguish pigments soluble in 

 water and pigments soluble in chloroform. The 

 former pigment is named by them " ferrine,'' and 

 contains iron combined with some proteid. The 

 pigment, soluble in alcohol and chloroform, contains 

 no iron, and appears to be identical with the chloro- 

 phyll of plants. 



In studies of the relation of the degree of acidity 

 of the urine and the percentage of uric acid con- 

 tained in it to the precipitation of the uric acid in 

 the form of gravel, W. J. S. Jerome finds that the 

 urine may be made to deposit uric acid, in healthy 

 persons through the ingestion of a sufficient quan- 

 tity of food rich in riuclein ; that some urines, after 

 an ordinary diet, have an abnormal tendency to the 

 precipitation of uric acid ; and that this tendency 

 is not always due either to the presence of a high 

 degree of acidity, or to a high percentage of the 

 uric acid in the urine, or to the coexistence of these 

 two conditions, however much such conditions may 

 favor the precipitation. 



In experiments to determine rather the sequence 

 than the nature of changes in urine resulting from 

 exercise, G. C. Garrott found that rapid but not 

 laborious exercise taken by a man in good muscular 

 condition, on ordinary diet and unrestricted fluids, 

 to a degree just short of the production of excessive 

 fatigue may be expected to produce some such re- 

 sults as (1) an excretion of urea rising to a maxi- 

 mum of possibly double the normal in about twelve 

 hours, and only regaining the usual level after about 

 thirty hours have elapsed, the increase beginning 

 immediately after, but not during the exercise ; (2) 

 an excretion of uric acid rising to a maximum not 

 greatly above the normal within six hours,and then 

 falling rapidly if the condition of the subject be 

 good and his "food sufficient, but rising to a higher 

 maximum and falling slowly if his condition be 

 poor and food deficient ; evidence that the rise in 

 this excretion occurs during the exercise or pre- 

 cedes that of urea is wanting ; (3) an increased ex- 

 cretion of acid, possibly during, and certainly im- 

 mediately after the exercise, less than that of urea, 

 but following the same course ; (4) an increased ex- 

 cretion of phosphates, certainly not during the exer- 

 cise, but immediately after, distinctly less than that 

 of acid, and therefore small, but on the whole accom- 

 panying that of the latter ; (5) an increased excretion 

 of sulphates, proportionate to that of urea, but of less 

 duration, and therefore of more intensity, this in- 

 crease commencing during the exercise, and reach- 

 ing a maximum of possibly three times the normal 

 within six hours, and probably earlier, but termi- 

 nating in twelve or fourteen hours ; (6) a decrease 

 in the excretion of chlorides, and the extent of 

 which will vary directly with the amount of sweat- 

 ing, and inversely with the condition of the subject 

 in relation to the exertion he is called upon to 

 make. Profuse and prolonged sweating induced by 

 Turkish baths at high temperatures may be ex- 

 pected to produce a reduction in the secretion of 

 urine, hardly to be prevented by drinking much 

 water; and a reduction in the excretion of chlo- 

 rides not, however, necessarily considerable. It 

 must not be expected to produce any noteworthy 

 effect on the excretion of urea, uric acid, urinary 

 acid, phosphates, or sulphates. 



Experiments by P. G. Hopkins and W. B. Hope 

 on seven individuals confirm the statement of P. 



Mares, made in 1887, that during the period of in- 

 creased nitrogen excretion that follows a meal the 

 increase of uric acid is of briefer duration than the 

 excretion of urea and occurs characteristically in 

 the earlier hours of the hyperexcretory period, a 

 fact which is difficult to reconcile with th'e view that 

 the uric acid takes origin from the nucleins of t In- 

 dict, upon which the earlier stages of digestion have 

 only a minimal influence. It is suggested by the 

 authors that of the total quantity of uric acid nor- 

 mally excreted, that portion which bears a more 

 immediate relation to food does not arise from nu- 

 cleins, but from some more soluble constituent of the 

 diet acting either as a direct precursor or as a fac- 

 tor in a synthetic process. 



Experiments were described to the International 

 Physiological Congress by Dr. Bedart, of Lille, in 

 which, subjecting the skin of the mammary region 

 of a number of women whose milk had gradually 

 fallen off or even failed on one side to electrical ex- 

 citation, he had succeeded in five cases out of eight 

 in restoring the secretion durably. In two cases a 

 breast which had failed began again to secrete milk. 

 With an average of four or five sittings of ten min- 

 utes each the density of the milk was usually in- 

 creased, and the nutrition of the child improved. 



Muscular System. At the meeting of the In- 

 ternational Physiological Congress P. J. Allen 

 showed that by the use of a very sensitive stetho- 

 scope he had ascertained that muscle, as such, makes 

 no sound during contraction. But if the movement 

 of the muscles is communicated to a membrane ca- 

 pable of sonorous vibration the membrana tym- 

 pani, for example a sound may be produced even 

 by a single muscular twitch. In order to produce 

 an audible vibration the twitch must be sudden. 

 Slowly contracting muscles produce no sound, as in 

 plain muscle or cold-blooded heart muscle. Other 

 muscles produce sounds whose intensity is in pro- 

 portion to the suddenness of their contraction. 



In a communication to the International Physio- 

 logical Congress of the results of his studies in the 

 frog, the turtle, and the cat of the process of mus- 

 cular fatigue, Dr. Frederick S. Lee represented that 

 the phase of contraction is lengthened greatly in 

 the turtle, slightly in the frog, and apparently not 

 at all in the cat. The one factor in the phenome- 

 non of fatigue that is common to these species is 

 the diminution of the lifting power of the muscles, 

 and this must be regarded as the essential factor in 

 the fatigue process. Of the two supposed causes of 

 muscle fatigue viz., decrease of contractile sub- 

 stance and accumulation of fatigue products with 

 poisoning of the muscle thereby the former appar- 

 ently plays no part in the phenomenon ; the latter 

 is the sole cause. Fatigue is a safeguard against 

 exhaustion. Attempts to demonstrate histological 

 differences between resting and fatigued muscle 

 gave negative results. 



Decerebrate rigidity s a term which was used by 

 C. S. Sherrington in a communication made to the 

 Royal Society in 1896 to designate a condition of 

 long-maintained muscular activity supervening on 

 removal of the cerebral hemispheres. Although 

 continued experimentation still leaves the author 

 in doubt concerning the actual focus of the origin 

 of the rigidity, he has supplemented his piv\ 

 communication with a further account of the phe- 

 nomenon and of some points connected with it. It 

 appears from this that "decerebrate rigidity is only 

 it type of extensor spasm of which allied examples 

 follow various other lesions of the cerebello-cere- 

 bral regions. The development of it in a limb is 

 largely determined by centripetal impulses coming 

 from the same. The contraction of the muscles 

 active in it can be readily inhibited by stimulation 

 of various regions of the central nervous system, 



