742 



PHYSIOLOGY. 



Explaining to the Physiological Society of 

 Berlin the experiments which he had made 

 with a view to the analysis of the muscular 

 sense, Dr. Goldschneider said that he had 

 availed himself of localized anaesthesia produced 

 by Paradic currents, and of the exclusion of 

 conscious volitional impulses. Perception of 

 motion takes place at the joints, and is not 

 affected by want of sensitiveness in the skin. 

 The time required for the perception of the mo- 

 tion is very short, and is unaffected by the posi- 

 tion of the 'limb. The muscles are not concerned 

 in perceiving the position of the limb, this being 

 dependent on the central nervous system, and the 

 recognition of resistance experienced in raising 

 and lowering weights is brought about by means 

 of the varying pressure exerted by the surfaces 

 of the joints against each other. The speaker 

 summed up the outcome of his researches as a 

 whole in the conclusion that the muscular sense 

 is compounded of three peripheral sensations 

 of a sensation of movement resulting from the 

 displacement of the condyles, of a sensation of 

 weight produced by the tension of the tendons, 

 and of a sensation of resistance due to the press- 

 ure of the articular surfaces against each other. 

 There is still another sensation that of posi- 

 . tion which results from pressure, tension, and 

 stretching of the skin and other local -stimuli. 

 Prof. Gad held, in opposition to these views, that 

 the perception of resistance is not directly a sen- 

 sation, but a judgment, based upon the relation 

 of the movement to the innervation and muscu- 

 lar tension. 



Miscellaneous. A series of investigations of 

 the growth of guinea pigs are described by Mr. 

 C. S. Minot, in a paper on " Senescence and Re- 

 juvenation.'' The author remarked some curious 

 variations in the growth of male and female 

 animals about the age of puberty, and a dimi- 

 nution in the rate of growth which occurs in 

 animals of both sexes, beginning about the end 

 of the fourth month, and which is greater in 

 amount and longer in duration in the female, is 

 believed to correspond to the post-pubertal re- 

 tardation in man. Each animal, according to 

 the observations, strives to reach a particular 

 size, but while some grow for a time too rapid- 

 ly, others grow too slowly ; but it appears that 

 if an individual grows for a period with excess- 

 ive rapidity, a period of slower growth imme- 

 diately follows, and vice versa. Those that re- 

 main behind for a time, if they continue in good 

 health, make up the loss soon after. Hence, to 

 dwarf a guinea pig permanently requires a very 

 long interference. The fact is brought out that 

 a female guinea pig may bear young without 

 impeding its own growth. But immediately 

 after delivery a great and rapid loss of weight 

 occurs, and continues for several days. The 

 diminution then proceeds at a slower' rate for 

 about three weeks, after which the recovery of 

 weight begins. In the process of growing old. 

 one of the most characteristic features is loss of 

 the power of growth. Mr. Minot concludes that 

 a progressive loss in the power of growth takes 

 place in guinea pigs, beginning almost immedi- 

 ately after birth, and he extends his conclusion 

 to embrace the supposition that a loss of growth 

 power is equally demonstrable in the case of 

 men and of other animals, and that there is lit- 



tle doubt that it is true at least of all mammals. 

 This conclusion raises the question whether 

 other animals do not obey the same law, and 

 sets, too, the more general problem whether in 

 all living beings there is not a certain impulse 

 given at the time of impregnation, and whether 

 this impulse does not gradually fade out, so 

 that from the very beginning of the new growth 

 there occurs a diminution in the rate of growth. 

 Concerning the action of alcohol on the sys- 

 tem, Chittenden's experiments show that in dogs 

 it causes no very striking specific action upon 

 the general metabolism of proteid matter. This 

 author supposes alcohol to act as a non-nitro- 

 genous food, protecting the nitrogen of the body 

 and somewhat lessening the nitrogenous output. 

 The excretion of uric acid was much increased by 

 the action of the alcohol, but no distinct 

 diuretic action was observed. Some inconclu- 

 sive experiments by Strassmann upon a litter of 

 puppies, some of which were given measured 

 quantities of spirits, tended to show that the 

 percentage weight was distinctly greater in the 

 alcohol dogs for liver and kidneys, but es- 

 pecially for the fat. In experiments upon man, 

 Strassmann endeavored to determine the elimi- 

 nation of alcohol by the lungs. In six experi- 

 ments, upon three persons, the average amount 

 excreted by the lungs during four hours was 5'1 

 per cent, of the quantity of alcohol taken. In 

 ft ve experiments, on two persons, an average ex 

 cretion of 1/7 per cent, of alcohol through the 

 kidneys was determined. Certain variations in 

 these experiments suggested the possibility of 

 the influence of renal peculiarities. Strassmann 

 agrees with Bodlander, with whose experiments 

 he compared his own, in supposing that the 

 greater part of the alcohol is disposed of in the 

 body and not excreted as alcohol. It appeared 

 incidentally in another series of experiments that 

 60 grammes of alcohol had no deleterious influ- 

 ence upon the digestive powers of a man accus- 

 tomed to take that quantity. The effect of the 

 different alcohols on the heart has been tabulated 

 by Dr. Hemmeter according to the average lessen- 

 ing of the amount of blood pumped out during 

 thirty seconds. The table shows the effects to be 

 in the following order, beginning with the small- 

 est and advancing to the largest : Ethyl, methyl, 

 propy], butyl, and amyl alcohol. It shows a re- 

 markable increase of the weakening effect of the 

 alcohol as the member of CH 2 molecules in- 

 creases, it being, with the exception of ethyl, or 

 common alcohol, twice as bad in the case of 

 each of the members as of its predecessor in the 

 series. The justness of the criticism set up in 

 these experiments has, however, been criticised, 

 and they can not be regarded as conclusive. 

 Attention is called by the author of the experi- 

 ment to the fact that ethyl alcohol appears from 

 the table to be the least deleterious of the series, 

 and that it fails to act on the heart as, according 

 to its chemical position, it should. 



In experiments bv MM. Charrin and Roger 

 to determine the effects of fatigue upon the 

 susceptibility to infection. 8 white rats which 

 had been severely exercised for four days in a 

 rotating squirrel cage were inoculated with the 

 charbon virus, and with them 4 other animals 

 that had not been exercised. Seven of the 8 

 tired animals died, while the 4 which had not 



