October 25, 1901.] 



SCIENCE. 



649 



nerves for the secretory glands has been 

 made more probable by Pawlow. The true 

 significance of this discovery lies in the fact 

 that it has enabled us to appreciate more 

 clearly the mechanism by which the secre- 

 tory glands, like other organs, adapt them- 

 selves so perfectly to the work which they 

 have to accomplish at different times. 



With pure digestive juices made thus 

 readily available, it is not surprising to find 

 interest in the study of their composition 

 renewed. The way has been opened for 

 more purely chemical investigations, such 

 as the recent one of Professor v. Nencki — 

 a colleague of Professor Pawlow — on the 

 character of the enzymes of the gastric 

 juice. From the general biological point 

 of view, one of the most interesting aspects 

 of the work of the St. Petersburg school is 

 the demonstration of the purposeful char- 

 acter of secretion into the alimentary 

 canal. Quantitatively and qualitatively 

 the work of the glands varies with the 

 character of the substances upon which 

 they exert their action at different times. 

 Changes in diet bring variations in the 

 character of secretion . Pawlow has broadly 

 expressed this viev/ in summarizing his 

 contributions to our knowledge of the spe- 

 cific excitability of the digestive glands. 

 He writes : " Our results have, we trust, 

 dispelled from our domain, once for all, the 

 unfruitful idea that the alimentary canal 

 is excitable by any agent whatsoever, me- 

 chanical, chemical or thermal, without re- 

 gard to the peculiarity of each specific di- 

 gestive task. At present, agencies such as 

 these, vigorously applied, must be regarded 

 merely as favoring or inhibitory influences, 

 not as the normal and determining factors 

 which excite secretory activity. In place of 

 gross uncertainty (Scheinwissen) we now 

 see the outlines of an artistic mechanism 

 which, like everything that we understand 

 in nature, exhibits an unusual degree of ex- 

 actness and utility in her processes." 



It remains to speak of Pawlow's work 

 (in cooperation with v. Nencki and others) 

 on the functions of the liver. Here again 

 a brilliant operative technique — the Eck fis- 

 tula, by which the portal blood is diverted 

 directly into the vena cava without entering 

 the hepatic capillaries — has inaugurated 

 progress. The splendid researches on the 

 seat of urea formation in mammals have 

 modified and shaped the current teaching of 

 this subject and other aspects of interme- 

 diary metabolism. What light they may 

 throw upon the pathogeny of certain abnor- 

 mal states, such as uraemia and diabetes, 

 can scarcely be foretold. 



Among the comparatively recent contri- 

 butions to physiological literature no book 

 has exerted a more stimulating influence 

 than Pawlow's ' Die Arbeit der Verdauungs- 

 driisen ' (J. F. Bergmann, Wiesbaden, 1898) . 

 It summarizes in suggestive chapters the 

 main achievements of the author in his 

 chosen field of work. Its original treat- 

 ment of the problems in this domain has 

 aroused the interest of both physiologists 

 and physicians ; and the work has already 

 served in fulfilment of the author's hope, 

 to further physiological science by promot- 

 ing a more active interchange of ideas 

 between the practitioner and the laboratory 

 worker. Pawlow's work has demonstrated 

 what Sir Michael Foster has written in 

 another connection: that /'the heart of 

 physiology is in the laboratory. It is this 

 which sends the life-blood through its 

 frame ; and in respect to this, perhaps, 

 more than anything else, has the progress 

 of the past years been striking." 



Lafayette B. Mendel. 



Sheffield Scientific School 

 OF Yale University. 



SCIENTIFIC BOOKS. 

 Report of the Sanitary Investigations of the Illinois 

 River and its Tributaries. The Illinois State 

 Board of Health, 1901. 



