PHYSIOLOGY. 



689 



permanent method of business between the 

 producer and the jobber. "The Practice of 

 Pharmacy," by Joseph P. Remington, of Phila- 

 delphia, is one of the most important works 

 ever published on the art of pharmacy. Oscar 

 Oldberg is the author of "An Outline of a 

 Course of Study in Practical Pharmacy," a 

 valuable text-book. "List of Tests" is a com- 

 pilation by Hans M. Wilder, which will be 

 found useful to the pharmacist. " The South- 

 ern Pharmacist " is the latest addition to the 

 periodical literature of this subject. The pub- 

 lication of " The Weekly Drug News," " The 

 Chicago Pharmacist," and "The Ephemeris," 

 has been discontinued. 



PHYSIOLOGY. The NerTons System. Investi- 

 gations have been made by several independent 

 observers of the sense of temperature, from 

 which some very interesting results have been 

 obtained. The measurements of Prof. Eulen- 

 berg, made with instruments especially de- 

 vised for the purpose, showed the existence 

 of a great diversity in the sense in differ- 

 ent parts of the body. The sensitiveness of 

 warmth was highest at the forehead and at 

 the dorsal side of the last phalanges, where 

 differences of 0*2 C. were distinctly perceived. 

 The least sensitiveness to warmth was shown 

 at the upper part of the anterior side of the 

 thigh, at the epigastrium, and in the median 

 line of the back, where only differences as 

 large as from 0'9 0. to 1/1 0. were perceived. 

 Sensitiveness to cold was likewise greatest at 

 the forehead, and least at the epigastrium and 

 back ; but the degree of sensitiveness to cold 

 did not always correspond with that of sensi- 

 tiveness to heat at particular parts of the body. 

 Certain spots show more sensitiveness to heat, 

 others to cold. From the circumstance that 

 the sense of temperature is more developed in 

 the hands and face, which are exposed, than in 

 those parts usually covered, the author infers 

 that the more delicate sense of temperature is 

 acquired. 



Dr. Goldschneider, working in the same line, 

 has found, by the application of the rounded 

 extremities of metallic needles, that there are 

 a very large number of points or nerve termini 

 in the skin which are sensitive to cold, and 

 others sensitive to warmth. They are unequal- 

 ly distributed over the body, and appear to 

 stand in a certain contrast to the fineness of 

 the sense of touch, being found more rarely 

 where that is very delicate. They appear to be 

 ranged together in the form of chains, of 

 which several, of cold or of warm points, as 

 the case may be, radiate from a definite center 

 on the skin. The chains of cold points never 

 coincide with those of warm ones, but the 

 two sets lie adjacent to each other. Excite- 

 ment of any of these points, by whatever cause_, 

 produces its specific sensation of warmth or 

 cold, not pain. The nerve termini may cease 

 to act in consequence of fatigue and ha- 

 bituation due to repeated stimulations, but, 

 after repose, they come decisively into opera- 

 VOL, xxv. 44 A 



tion again at the same spots. The number of 

 warm points is less than that of cold points, 

 and there are parts of the skin where there 

 are neither ; and some parts contain cold but 

 no warm points, while uo part contains warm 

 without adjacent cold points. Dr. Goldschnei- 

 der agrees with Weber, that a rise in tempera- 

 ture of the skin generates a feeling of warmth 

 by exciting the warm nerve termini, while a 

 depression of temperature creates the feeling 

 of cold by exciting the cold termini. The 

 sense of pressure is also distributed over the 

 skin in its own special points, likewise ar- 

 ranged in chain-like rows which radiate from 

 particular centers ; and the localization of the 

 sense of pressure is still finer than that of tem- 

 perature. 



Prof. Eulenberg, repeating Dr. Goldschnei- 

 der's earlier experiments, found them generally 

 confirmed; and, as a whole, his conclusions, as 

 recited in the paper above quoted, and those 

 of Dr. Goldschneider, were in harmony. 



Dr. Blaschko having found, in the course 

 of his investigations into the development of 

 the skin, that the hair-roots are provided with 

 a rich nerve-plexus in the same manner as the 

 touch-corpuscles in the hands and feet, was in- 

 duced to examine the hairs in respect of their 

 sensibility to pressure. When he took a stiff 

 hair, a little curved at the tip, and stroked the 

 skin with it, he had a sensation only when 

 he touched a fine hair. By this and other 

 means he became convinced that the hair-pa- 

 pilla possessed a degree of sensibility which 

 entitled them to be placed in a series with 

 the touch-papillaa. While, however, the touch- 

 corpuscles had to be drawn hither and thith- 

 er over the object to be touched, in the case 

 of the touch-hairs the body had to be waved 

 over them. Dr. Blaschko was, therefore, of 

 opinion that a direct and an indirect, or a 

 papillary and a ciliary, feeling of the skin 

 had to be distinguished. The first performed 

 its functions at the unhaired cutaneous spots 

 the touch-balls of the hand and the foot, and 

 at the lips by means of the touch-corpuscles. 

 The indirect or ciliary sensations, on the other 

 hand, were furnished by the fine hairs cov- 

 ering the whole body, which were, properly, 

 touch-hairs. If, at a limited spot of the skin, 

 the fine hairs were shaved away, the delicate 

 sensations of pressure would disappear, and a 

 large hiatus would be perceptible on waving 

 that part of the skin with the stiff hair, at 

 which nothing would be felt. 



It has been understood that every proposed 

 theory in respect to the nature of nerve-force 

 must take account of the transmission of a 

 stimulus along the nerve with undiminished 

 intensity, and of the exhaustion of a nerve by 

 continued stimulation. Upon the latter point 

 the experiments of Bernstein, which indicated 

 that, while it took longer to exhaust a nerve 

 than to exhaust a muscle, a nerve may be ex- 

 hausted by from five to fifteen minutes' te- 

 tanic stimulation, have usually been regarded 



