676 



PHYSIOLOGY. 



healthy natural secretion of the salivary glands 

 of the stomach or the pancreas, is not such as 

 to interfere with any of their digestive func- 

 tions. 



In experiments upon the relative digesti- 

 bility of various feeding-stuffs, adopting Stut- 

 zen's method, E. F. Ladd employed as a men- 

 struum a solution of scale pepsine. The sub- 

 stances experimented with were classified as 

 " hay and coarse fodders," " by-products," and 

 u grains." Of the feeds examined in per cent, 

 of digestibility of the albuminoids, he reports, 

 bean-meal stands the highest, linseed-meal (old 

 process) next, and pea-meal but little less, 

 while mixed hay of rather inferior quality, but 

 similar to much hay fed, stands lowest. The 

 old-process linseed-meal shows a higher per 

 cent, of digestibility than the new process, a 

 difference which is due, very likely, to the par- 

 tial cooking of the meal by steam during the 

 process of oil-extraction and preparation of the 

 meal for feed. Cotton-seed meal, much the 

 richest substance examined, gives a high coef- 

 ficient for digestibility. A marked difference 

 existed between different qualities of hay, show- 

 ing the effects of the manner of curing. Of 

 the raw and cooked foods examined, in every 

 instance the higher digestion coefficients were 

 obtained for the raw foods, and an examina- 

 tion of the table of analysis shows an actual 

 loss in albuminoids by cooking, and a change 

 in the fat rendering it insoluble in ether, and 

 unacted upon by acids or alkalies of the 

 strength used for fiber determinations. 



The influence of hot drinks on digestion has 

 been investigated by V. E. Nyeshel on the per- 

 sons of twenty hospital surgical patients. When 

 not more than three tumblerfuls of hot tea had 

 been swallowed, digestion was found to have 

 proceeded just as well as without it, but a larger 

 quantity of hot tea retarded the process. As 

 between hot and cold food no difference was 

 found. 



Three hypotheses have been advanced to ac- 

 count for the structure of the " edible bird's- 

 nest"; the first, that it is partly, at least, of 

 vegetable origin, and consists of pieces of alga 

 fastened together by the bird's saliva ; the sec- 

 ond, that the material is made by the bird from 

 fish-spawn, or is collected from mollusoa ; the 

 third, which was advanced by Sir Everard 

 Home, and sustained by Bernstein in the 

 "Journal filr Ornithologie," is that the mate- 

 rial consists entirely of an animal secretion, 

 and is essentially the product of some peculiar 

 glands possessed by the bird. Mr. J. R. Green, 

 of Trinity College, has subjected some of the 

 material to a microscopic examination in order 

 to ascertain whether any evidences of vegetable 

 structure can be detected. None were found, 

 and this fact was regarded as bearing adversely 

 to the theory of a vegetable origin. The re- 

 sults of the chemical tests bore in the same di- 

 rection. Mr. Green concludes from these facts, 

 combined with the more positive indications 

 afforded by his experiments, that the substance 



is an animal product so closely allied to mucine 

 that it may be said to be a variety of it, and 

 that there can be little doubt that it is the re- 

 sult of the activity of certain glands described 

 by Bernstein as being remarkably developed in 

 the nest-building season, and as atrophy ing im- 

 mediately afterward. 



Zweifel, of Zurich, has made some observa- 

 tions on the rate of absorption through the 

 stomach, using iodide of potassium, which was 

 introduced inclosed in gelatine capsules. When 

 so given, in doses of three grains, the time 

 taken for the appearance of the salt in the 

 saliva, in the case of the healthy individual, 

 varies from eight to ten minutes ; this rate of 

 absorption remaining much the same on differ- 

 ent days. The salt appears in the urine and 

 the saliva at about the same time, although on 

 the whole somewhat earlier in the latter than 

 in the former. Absorption is always much de- 

 layed when the stomach is full. In almost all 

 diseases of the stomach absorption tends to be 

 delayed, this tendency being most marked in 

 dilatation and cancer, and least so in chronic 

 catarrh. In ulcer of the stomach the delay is 

 only slight, but in ulcer of the stomach with 

 extensive recent ulceration of the mucous 

 membrane, it may be considerable. If in the 

 empty condition of the stomach absorption is 

 longer delayed than twenty minutes, there is 

 every reason to believe that we have to deal 

 either with dilatation of the stomach or with 

 cancer of the pylorus, or both together, pro- 

 vided always that the existence of any fresh 

 ulceration has been excluded. A differential 

 diagnosis between cancer, ulcer, and chronic 

 catarrh of the stomach is not always possible 

 from the rate of absorption alone. The differ- 

 ences between the rates of absorption in the 

 empty and full conditions of the stomach are 

 less marked in diseases of the stomach than in 

 health. During fever the rapidity of absorp- 

 tion is diminished, but it is not affected by the 

 height of the fever. 



Muscular System. Drs. Mosso and Maggiora 

 have reported to the Accademia dei Lincei con- 

 cerning experiments which they have recently 

 made on the laws of fatigue. They employed 

 a mechanism, by means of which they could 

 observe the variations of the efforts put forth 

 by a finger in lifting a weight until entire ex- 

 haustion had set in. The mechanism was then 

 readjusted in such a way that the operator's 

 whole arm remained motionless with the ex- 

 ception of the muscle corresponding to the 

 finger in action. From the tracings of the vari- 

 ations of the muscular effort it was shown that 

 every individual under experiment gave a spe- 

 cial characteristic trace, which at once distin- 

 guished his effort from those of the others. Re- 

 sistance to fatigue was seen to be different at 

 different hours of the day, and to be variously 

 affected by the influence of food. Studies 

 were also made of the problem of the disposing 

 of the pauses, so as to make the outlay of force 

 as economical and effective as possible. Accord- 



