August 15, 1895] 



NA TURE 



369 



M. ( "1111116111111, in an admirable paper on the metallo- 

 graphy of the alloys of copper presented to the French 

 "Commission des Methodes d'essai des Materiaux dc 

 Construction," ' has given evidence that it is possible to 

 pronounce with certainty, by the examination of etched 

 surfaces of examples of the alloys, which deoxidiser has 

 been employed. 



It remains to be seen in what way the mechanical 

 properties of steel are connected with the structural 

 changes revealed by micrographic examination. In 

 cver>' specimen of steel, as has already been stated, at 

 least three great molecular changes are produced as the 

 metal is raised from the ordinarj- temperature to a white 

 heat. The belief that the rearrangement of atoms in 

 the molecule of iron 'which is, in fact, allotropyj is really 

 fundamental to these molecular changes, is rapidly gain- 

 ing adherents, but authorities on hardening of steel are by 

 no means in accord as to the true significance of allotropy 

 in relation to that important industrial operation. The 

 w riter of this paper has long declared himself to be a pro- 

 nounced allotropist, and many patient experimenters arc 

 hard at work at the jiroblem. M. Charpy,- for instance, had 

 already pointed to the peculiar beha\ iour of steel under 

 longitudinal stress, as proof that the metal undergoes 

 allotropic change. He now seeks, by an elaborate series 

 of experiments, to ascertain whether the mechanical tests 

 of steel which has been quenched at definite temper- 

 atures, support Osmond's view as to the significance of 

 the part played by allotropy of iron in the hardening of 

 steel. Charpy's opinion seems to be that, on the whole, 

 his experiments do not afford conclusive evidence 

 in support of Osmond's view. It may, however, be 

 urged that in the case of steel, mechanical tests could not 

 be expected to afford decisive evidence in relation to 

 the theoretical significance of allotropy, because, as M. 

 Osmonds micrographic work shows, the structure of 

 steel is so complex and varies so much with thermal 

 treatment. It is, of course, ultimate structure which 

 determines the strength and elasticity of steel, and none 

 of us claim that allotropy is the sole factor in the 

 production of structure. 



The magnetic behaviour of steel, on the other hand, 

 as .M. Curie has recently pointed out, is greatly influenced 

 by temperature, for, within the range of 20' to 1350', 

 rapid \ariations in magnetic properties of soft iron reveal 

 themselves at about 750, 860', and 1280°. This, as he 

 says, is favourable to the views of ^I. Osmond, because 

 on independent evidence we are led to conclude that 

 at temperatures near these points the metal undergoes 

 allotropic modifications. 



It is to be hoped that microscopic analysis will soon 

 take its place in the ordinary routine of every steel works 

 laborator)-, and it should be added that in this country 

 two well-known authorities, Mr. T. .Andrews and Mr. J. 

 K. .Stead, constantly employ it, while Mr. .-X. Sauveur'' 

 has originated the system already in the works of the 

 Illinois .Steel Company. \V. C. Ror.KKTS-.VusTKN. 



THE SClE.VriFIC RKSII.TS OF THE ANNUAL 

 MEETING OF THE BRFT/SH MEDICAL AS,- 

 SOCIA TION. 



•X* HE annual meeting of the British Medical Associa- 

 -*• tion is. no doubt, increasing in importance, since it 

 is becoming a congress for the demonstration of the advance 

 of medicine. The work of the meeting may be con- 

 sidered as belonging to two classes, the practical and the 

 scientific. Many, no doubt, who attend the annual 

 meeting, do so with the object of gaining practical help 



1 " .\nal>-sc Micrographique des .'\lliagcs." {Comptcs rendits^ vol. c.w. 

 p. 3(3. July 25. 1893.) 



- ■' Bull, dc )a Soc. d'Ericouragcnicnl," vol. x. 1895, p, 660. 

 * " Trail*. .Amer. See. .Mining Engineers," vol. .\xii. p. 546. 



NO. 1346, VOL. 52] 



in both the medical and the surgical treatment of their 

 patients ; and this help the annual meeting g^ives in 

 abundance. One of the most important parts of the 

 meeting, however, is that which is occupied with the 

 progress of scientific medicine, and consists not so much 

 in the announcement bf startling discoveries (for with 

 these medicine has but little to do;, but in the revision 

 and criticism of the facts discovered by experiment and at 

 the bedside. 



.Medical science is becoming more e.xact, as the know- 

 ledge of the functions of living tissues 'physiology) and 

 their changes in disease pathology; increases. 



It is not so many years ago when the chief subject in 

 what was called physiology was histology, or the struc- 

 ture of the tissues. Physiology proper then rapidly 

 progressed, and although at first it was considered from 

 a somev\hat too physical standpoint, and indeed is still 

 so considered by some, yet it has received an enormous 

 impetus by being associated with the study of chemistry 

 and of the action of the chemical constituents of the 

 body on the living tissues. This is evidenced in the 

 excellent address on " Internal Secretion," given by Prof 

 E. A. .Schafer, F. R.S., of University College, a subject 

 which in its scientific aspects is of a quite recent develop- 

 ment. .\ secretory organ may, like the stomach, saliv ary 

 glands, &c., separate materials from the blood and pour 

 them into a cavity, in which they are utilised ; this may 

 be called external secretion. On the other hand, " some 

 secreted materials are not poured out upon an external 

 surface at all, but are returned to the blood ' ; these may 

 be called internal secretions. Although it is probable 

 that in the widest sense everv- tissue has an internal 

 secretion, yet this is most obvious in the ductless glands, 

 such as the thyroid, the suprarenal bodies, and the 

 pituitary body. But in one gland with an important 

 external secretion, viz. the pancreas, there is also an in- 

 ternal secretion which is of great value in the economy. 



The subject of internal secretion has developed hand 

 in hand with clinical medicine, and it was the obser- 

 vation of patients which first, as in the case of the thyroid, 

 gave the clue to the line of investigation. It is im- 

 possible in this place to give a detailed account of 

 Prof. Schiifers address ; it is well worthy of study 

 by ever)" one interested in the progress of biological 

 science. It will not be out of place, however, to illustrate 

 the subject of internal secretion by quoting as examples 

 the investigation of the pancreas and the suprarenal 

 capsules, the latter of which has been the subject of 

 special study by Prof Schiifer, in conjunction with Ur. O. 

 Oliver and .Mr. Moore. 



The association of disease of the pancreas with the 

 presence of sugar in the urine has long been noted ; 

 although only a certain proportion of cases of diabetes 

 show any great changes in this organ. If the pancreatic 

 juice be diverted from the intestine, or if the duct be 

 blocked, the animal experimented upon does not die, 

 there is no glycosuria, nor does it apparently suffer any 

 great nutritional change. If, however, the pancreas be 

 totally extirpated, glycosuria appears, and the animal 

 invariably dies ; this docs not occur, however, if only a 

 part of the organ be removed. More than this, if a 

 portion of living pancreas be successfully grafted into an 

 animal from which the organ is subsequently completely 

 remov ed, no evil results follow. Besides its obvious and 

 important function of secreting a digestive juice, the 

 pancreas therefore produces some material which it gives 

 to the blood, and which is essential for the continuance of 

 life ; this is the internal secretion. On the other hand, 

 it is suggested that the organ nominally separates and 

 transforms some toxic substance which is fatal to exist- 

 ence ; this is the theory of auto-intoxication. The internal 

 secretion of the suprarenal capsule is more obvious, per- 

 haps, than that of the pancreas. The capsule is a duct- 

 less gland ; it has no external secretion. The complete 



