PHYSIOLOGY. 



539 



one direction only. The magnetic moment due to 

 the magnetization is affected neither by duration 

 nor number of magnetizations. With sudden re- 

 moval of the magnetizing force, the residual mo- 

 ment is somewhat smaller than with gradual re- 

 moval, or removal by steps of not more than 3 

 per cent. ; but a sudden and a gradual magnetiza- 

 tion has the same effect. Contrary to the gener- 

 ally accepted results, the author finds that a 

 small value of H, amounting to O.Ooo, produces a 

 residual magnetic moment equal to G per cent, 

 of the temporary moment. The author explains 

 his results according to the theory that assumes 

 the existence of frictional or cohesion forces be- 

 tween the molecular magnets. 



Detection of Ancient Magnetic Fields. Brun- 

 hes and David (Comptes Rendus, July 15) have 

 applied Folgheraiter's idea that the direction of 

 the magnetic field during the baking of bricks 

 may be ascertained by measuring their permanent 

 magnetism to the beds- of clay in the Puy-de- 

 Dome region which have been baked by lava- 

 streams. Small cubes of the baked clay were 

 cut out, and the directions of their permanent 

 magnetization were determined. In the case of 

 cubes taken from the same -lava-stream the re- 

 sults agree fairly well; cubes taken, however, 

 from different lava-streams give widely divergent 

 results, and the authors suggest that the method 

 might be of use in determining whether two lava- 

 streams were contemporaneous or not. 



PHYSIOLOGY. Historical and Theoret- 

 ical. In the section of physiology of the Brit- 

 ish Association. Prof. McKendrick, of Glasgow, 

 began his presidential address on the relation of 

 physical and chemical structure as understood at 

 present in our conception of the structure of 

 living matter, with a reference to the advance that 

 had been made in physiology during the past 

 quarter of a century. In its progress physiology 

 had proved a living and logical inductive science, 

 grappling its problems successfully by the help of 

 the same laws that physics and chemistry apply 

 to non-living matter and its phenomena. It had 

 in the last quarter of a century proved fruitful 

 of discovery to an astonishing extent. Many of 

 its discoveries were of high practical use in medi- 

 cine as well as of theoretical value. It had struck 

 deep into the soil, acquiring many new data of 

 extreme accuracy, and obtaining much profounder 

 insight into the concatenations of the machinery 

 of life. The phenomena of muscular contraction, 

 the process of secretion by gland cells, the mutual 

 synergy of organs as illustrated by internal secre- 

 tion, the functional architecture of the nervous 

 system, the mechanics of rejuvenescence of proto- 

 plasm by sexual recombination (fertilization) ; 

 all these branches of the physiological tree of 

 knowledge had, under the cultivation of the last 

 twenty-five years, grown greatly in extent and 

 yielded blossom and valuable fruit. Facts more 

 accurate and theories more profound had drawn 

 their science closer to the elder sister sciences of 

 more systematic measurement, and at the .same 

 time had created, it must be admitted, a gap be- 

 tween it and subjects with which it had formerly 

 been associated in teaching. Its advance had 

 widened the educational field and educational 

 worth of physiology, releasing it from former re- 

 striction to narrower technical applications. Save 

 in mathematics, knowledge can not be absolute in 

 any domain of science. Physiology shared with 

 the sister sciences their birthright of problems 

 that were, to speak a paradox, the more insoluble 

 the farther we progressed toward their solution. 



The volume on the history of physiology during 

 the sixteenth, seventeenth, and eighteenth Oen- 



turies, by Sir Michael Foster, p., ,ii H<1 in the 

 Cambridge University Press l)r : ,>> ..: i i( s, con- 

 sists of lectures delivered m , ,,i |<)oo 

 before the Cooper Medieal Colic < . icisco 

 Cal. Without claiming to be a. < - I, M v ' 

 of the subject, the book contain , :, '\. 

 of the chief advances made in phy-i- - . 

 time of Vesalius until the beginning oi tin 

 teenth century. 



The lines along which sound theory would di- 

 rect the teaching of physiology in medical schools 

 are laid down by Dr. W. T. Porter, of the Harvard 

 Medical School, in the Philadelphia Medical Jour- 

 nal, in a series of maxims as follow: " Deal so far 

 as possible with the phenomena themselves, and 

 not with the description of them. Where the 

 fundamental experiments can not be performed, 

 fill the gap with the original protocols from the 

 classical sources. Associate facts which the 

 student can observe for himself with those which 

 he can not observe. Use as the basis of profes- 

 sional instruction, where practicable, the facts 

 and methods to be used by the student in earn- 

 ing his living. Teach the elements by practical 

 work. Let the student state his observations and 

 results in a laboratory note-book, which, with 

 the graphic records of his experiments, shall form 

 one of the requirements for the degree. Control 

 his progress and remove his difficulties by a daily 

 Written examination and a daily conference, in 

 which the instructor shall discuss the observa- 

 tions made by the student, and supplement them 

 from his own reading. . . . Demand of every stu- 

 dent a written discussion of some very limited 

 thesis, giving the results of the original investiga- 

 tors, together with any observations the student 

 hae made for himself. Give the more capable 

 students opportunity for original experimental 

 work. Toward the end of the instruction, when 

 the student is ripe for such work, offer a liberal 

 number of courses of didactic lectures, with dem- 

 onstrations. . . . These lectures should show the 

 student the historical development of scientific 

 problems, the nature of scientific evidence, and the 

 canons of criticism that help to sift the wheat 

 from the chaff of controversy. From the begin- 

 ning to the end of the instruction hold fast to 

 concentration, sequence, and election." Concen- 

 tration upon the one subject in hand, a correct 

 sequence of study, and election, from the numer- 

 ous objects of study that present themselves, of 

 those which are directly associated with his fu- 

 ture work as practitioner or investigator. To 

 meet the needs of the several classes of students, 

 the department of physiology should provide the 

 primary course, suitable for every student of bio- 

 logical science, including medicine. An advanced 

 course, intermediate between the primary course 

 and research, and opportunities for physiological 

 research. 



The theory that life is a form of energy nearly 

 allied to chemism has been further elaborated by 

 Prof. Giglio-Tos in a book entitled Les Problemes 

 de la Vie. This author assumes that the function 

 of assimilation, or the transformation of digested 

 food into an integral part of the organism, is a 

 chemical phenomenon, quite analogous to the 

 transformations which many organic chemical 

 compounds may be made to undergo in labora- 

 tories. Having established five fundamental con- 

 ditions to which a molecule must conform in order 

 to manifest the phenomena of assimilation, the 

 author explains his theory of the process. It sup- 

 poses that protoplasm consists of ultimate assimi- 

 lative living particles called " bimolecules." which 

 unite into polymolecular aggregates called bio- 

 mores, which in turn unite into an aggregate 



