890 



SCIENCE. 



[N. S. Vol. XXI. Xo. 545. 



except in the anomalous animals that sur- 

 vive indefinitely, shows remarkable con- 

 stancy even in dogs which live several 

 weeks. Thus, after double vagotomy, a 

 regulation of the heart rate is again devel- 

 oped which tends to bring it back towards 

 the normal, while in the ease of the respira- 

 tion, such a tendency, if it exists, is much 

 feebler. In the exceptional animals the 

 ratio shows a marked tendency, even in the 

 first few days, to retiirn towards normal, 

 both by a diminution in the pulse rate and 

 by an increase in the rate of respiration. 



3. After section of the whole of one 

 vagus and about half of the other, the re- 

 maining vagus fibers are sufficient to keep 

 the rate of the heart and respiration almost 

 normal. With how small a proportion of 

 vagus fibers intact, dogs (apart from the 

 anomalous cases mentioned) will survive, 

 remains to be determined, although it has 

 been found that artificial stimulation of 

 a comparatively small number of fibers 

 causes the usual effects on the heart and 

 respiration. 



The Influence of the Blood Pressure and of 

 Atropin and Nicotin 07v Experimental 

 Glycosuria: J. J. R. MacLeod and D. H. 

 DoLLEY. (Preliminary communication.) 

 The glycosuria which follows puncture 

 of the floor of the fourth ventricle in rab- 

 bits can be inhibited by the administration 

 of nicotine. This may act either by par- 

 alyzing the synapses of the centrifugal 

 fibers from the so-called glycosuric center 

 as they pass through the upper thoracic 

 sympathetic ganglia, or be due to a fall in 

 blood pressure. 



By applying nicotin directly to these 

 ganglia the glycosuria produced by stim- 

 ulation fif the central end of the vagus is 

 also inhi])itcd, but the marked fall in blood 

 pressure which follows the operation neces- 

 sary for exposing the ganglia, and not the 



effect of the drug on the synapses, may be 

 the cause of the inhibition. 



In dogs a fall of bl'ood pressure to 40 

 mm. — produced by hemorrhage — causes the 

 glycosuria produced by stimulation of the 

 central ends of the vagi to disappear. 



The injection of nicotin into dogs or rab- 

 bits rendered glycosuric by vagal or de- 

 piessor stimulation does not, as a rule, have 

 any influence in the amount of sugar in the 

 urine. 



Atropin has no constant effect either on 

 puncture glycosuria or on that due to stim- 

 ulation of the vagus or cardiac depressor. 

 Sometimes it causes the amount of si;gar in 

 the urine to diminish markedly, at other 

 times it has no effect. No explanation can 

 be offered for this result. 



Chas. W. Greene, 



Secretary. 



SCIEXTIFIC BOOKIE. 

 The Phase Rule and Its Applications. By 

 Alex. Findlay. With an Introduction to 

 the Study of Physical Chemistry by Wil- 

 liam Ramsay. 13 x 18 cm. ; pp. Ixiv + 313. 

 New York, Longmans, Green and Co. 1904. 

 Price, $1.60. 



While physical ehemistrj^ in a certain sense 

 is as old as physics or chemistry, the appear- 

 ance of Ostwald's ' Lehrbuch der allgemeinen 

 Chemie ' some twenty years ago really marks 

 the beginning of a new era. Since that time 

 physical chemistry has developed along two 

 quite distinct lines. Van't Hoff brought for- 

 ward the osmotic pressure theory of solution 

 and Arrhenius the theory of electrolytic dis- 

 sociation, the two resulting in what maj' be 

 called the quantitative theory of dilute solu- 

 tions. Most chemists are fairly familiar with 

 the development of this theory. Not so many 

 people have interested themselves in the second 

 line of work. Roozeboom felt the need of a 

 basis of classification for the numerous double 

 salts and compounds which are met with in 

 inorganic chemistry. He found this in the 

 phase rule of J. Willard Gibbs and he has 

 developed it until it is now seen to be the one 



