058 



PHYSIOLOGY. 



the cylinder. It was found that, when the 

 sound occurred before the contact of the lever 

 with the finger, no error was ever. made. The 

 subject invariably heard before he felt. When 

 the two were synchronous, the same result was 

 observed ; and even when the tactile stimulus 

 was applied before the auditory, the latter was 

 still first perceived, and this even when the 

 former was ^ of a second before the latter. 

 From a consideration of all his experiments, 

 the author finds that, of the three sensations 

 he has studied, vision is the most rapid ; to 

 this succeeds hearing, the transmission of which 

 lasts y 1 ^ of a second longer than visual trans- 

 mission; and, lastly, touch, which in the case 

 of the hand lasts ^ T of a second longer than 

 visual transmission. 



The Digestive System. Investigations have 

 been made by F. W. Pavy to ascertain the 

 changes undergone by the four chief carbo- 

 hydrate elements of food, viz., grape-sugar, 

 cane-sugar, lactine, and starch, during diges- 

 tion. Beginning with the stomach, the at- 

 tempt was made to follow the changes in 

 those substances as they proceed toward ab- 

 sorption up to their arrival within the portal 

 system of vessels. The experiments were per- 

 formed on the digestive organs of freshly-killed 

 rabbits and other animals, portions of the stom- 

 ach or intestines being left in contact, for a 

 given time, with solutions of known weights 

 of the carbohydrate in question, and the cop- 

 per-reducing value of the substance, after this 

 digestion, was compared with that which it 

 had been found to have before contact with 

 animal substance. Inasmuch as grape-sugar is 

 characterized by the property of possessing the 

 same reducing power after treating with sul- 

 phuric acid as before, while the carbohydrates, 

 which represent steps in an operation of which 

 glucose is the final product, are altered in re- 

 ducing power by the action of the acid, the 

 author took the precaution to boil one portion 

 of the modified liquid with sulphuric acid in 

 all cases before estimating the reducing power. 

 The copper-reducing value of the digested liquid 

 may thus be compared with that of glucose, 

 while the relation of the modified product to 

 glucose is also ascertained. The most striking 

 result of these experiments is the indication 

 that transformation of glucose into bodies of 

 lower reducing power is possible under the in- 

 fluence of a ferment existing in the stomach 

 and intestines. Boiling of the animal substance 

 with water, previous to the experiment, was 

 found to annul the. action of this ferment. The 

 latter body seems to exist rather within the 

 walls of the vessels examined than upon the 

 mucous surface. So far as the experiments 

 have gone, the author regards them as indi- 

 cating that the ferment is more abundant in 

 the stomach and intestines of the rabbit than 

 in those of the dog, cat, horse, sheep, or pig. 



Drs. G. F. Yeo and E. F. Herroun have made 

 investigations of the composition of human bile 

 obtained from a fistula of a patient suffering 



from jaundice, with comparisons with bile 

 from the gall-bladder of the same person. 

 Difficulty was met in making accurate estima- 

 tions of the daily secretions of bile, on ac- 

 count of the unavoidable leakage into the dress- 

 ings of the wound. As nearly as could be 

 determined, the mean quantity was about 13'2 

 ounces per twenty-four hours ; this is consid- 

 erably below what other authors have esti- 

 mated for the daily secretions of a well man. 

 No difference in the rapidity of secretion could 

 be detected at any time, nor any increase after 

 the small meals of which the patient partook. 

 The total solid residue was determined on five 

 different occasions within a period of twelve 

 days. The average was 1-3468 per cent. Com- 

 bining this with other determinations made by 

 Jacobsen, 2'26 per cent., and Ranke, 3*16 per 

 cent., we have a mean of 2'25 per cent, solid 

 constituents in fistula-bile, as against a mean 

 of 9-021 per cent, for gall-bladder bile, as de- 

 termined by Trifanoski from persons who had 

 died of various diseases, and 13-96 per cent., 

 as determined by Gorup-Besanez, and 14'04 

 per cent, by Frerichs, trom healthy persons 

 who had died suddenly. These determina- 

 tions indicate that the bladder-bile of healthy 

 persons is only half as rich again in solids as 

 that of persons who have died from disease, 

 while bile from the gall-bladder, even of the 

 latter, contains four times as much of solids as 

 that obtained from a fistula. 



Gauthier has found, in normal human saliva, 

 an alkaloid-like, non-nitrogeneous substance, 

 forming a crystallizable compound with chlo- 

 ride of gold and platinum, which, in its physio- 

 logical action, resembles the ptomaines, or the 

 alkaloids developed in cadavers ; injected into 

 animals, it acts like snake-poison. Budwin, 

 making experiments in the same line, obtained 

 negative results. 



A widely distributed coloring-matter, which 

 is regarded as beyond doubt a chlorophyl pig- 

 ment, has been discovered in the livers of in- 

 vertebrates by Mr. C. A. MacMunn, and has 

 been called by him entero-chlorophyl. It ap- 

 pears to differ from plant-chlorophyl, in that 

 treatment with nitric acid makes the solution . j 

 slightly greenish, although previously it may 

 have been yellow. Mr. MacMunn's paper re- 

 lates his researches with the spectroscope, and 

 discovery of this pigment in oysters, crustace- 

 ans, and star-fishes. Much evidence has been 

 adduced to show that entero-chlorophyl is 

 synthetically formed in the body of its animal 

 possessor. 



The process of rumination has recently been 

 studied by Prof. Luch singer, in a course of ex- 

 periments on the goat. As disturbance of the 

 animal is very likely to interrupt the process, 

 the goats experimented on were narcotized 

 with morphia, which numbs painful sensa- 

 tions but interferes but little with reflex ac- 

 tion. It was found that pressure with the 

 hand upon the wall of the paunch readily initi- 

 ated the act of rumination. There was first 





