136 



SCIENCE. 



[N. S. Vol. V. No. 108. 



tests of abilitj' were made by throwing a 

 ball, the dogs competing on equal terms for 

 its possession and for the privilege of bring- 

 ing it back. In two series of tests made in 

 this way, 1,400 and 1,000 balls being shown, 

 the alcoholic male has shown an efficiency 

 of only 32% and 44^ as compared with 

 that of his brother. On account of differ- 

 ences in condition, no satisfactory test has 

 been possible as j'ct with the females. 



A series of photographs taken at intervals 

 during the research was exhibited. 



The physiological action of nitrous oxide. G. T. 



Kemp. 



It has been claimed that the supposed 

 ansesthetic properties of nitrous oxide are 

 due to its asphyxiating power. A careful 

 comparison of its physiological action with 

 that of a neutral gas, such as nitrogen, 

 shows that in nitrous oxide separate anaes- 

 thetizing and asphyxiating powers may be 

 demonstrated. To supplement this, a series 

 of analyses of the blood gases of animals 

 asphyxiated by nitrous oxide shows that 

 anaesthesia maj' be obtained with this gas 

 while the blood is still carrying sufficient 

 oxygen to meet the demands of the system. 

 Work with nitrous oxide and oxygen indi- 

 cates that soon an anajsthetic may be rec- 

 ommended, which will be effective and yet 

 avoid the objections applying to chloroform 

 and ether. 



On bactericidal effects of lynvph from the thoracic 

 duct. (With Dr. Charles ISTorris.) S. J. 

 Meltzer. 



In contrast to the surprising statements 

 of Max Neisser that the lymph coming 

 from the thoracic duct does not contain 

 bactericidal properties, the authors find the 

 lymph coming from the thoracic duct of 

 dogs to be distinctly germicidal for the 

 typhoid bacillus. The bactericidal power 

 of the lymph differs from that of the blood 

 in not becoming exhausted even after days. 



N"eisser apparently employed unreliable 

 methods. 



On the interpretation of the so-called latent 

 period of the motor nerve-endings, and on the 

 supposed demonstration of their exhaustihility. 

 F. S. Locke. 



The replacement by mere contact of the 

 continuity formerly believed generally to 

 exist between irritable structures would 

 seem to necessitate more attention being 

 given to the ' discharge hj^pothesis,' on 

 which Kiihne has especially insisted — 

 namely, that the motor nerve-fibre stimu- 

 lates the muscle-fibre by means of its ac- 

 tion current, which acts as an electric stim- 

 ulus. The author's experimental results 

 favor the view that the so-called latent 

 period of the motor nerve-endings, which 

 has been held by Bernstein and others to 

 be crucial against the hypothesis, may be 

 due to the nature of the electric stimula- 

 tion by the action current. It was found 

 that the secondary stimulation of one frog's 

 sartorius muscle by the action current of 

 another is associated with a measurably 

 longer latent period than is stimulation 

 with an induction shock. 



Another argument against the ' discharge 

 hypothesis ' might conceivablj'^ be founded 

 on the supposed exhaustihility of the motor 

 nerve-endings. It was found, however, that 

 if the curarised sartorius be continuously 

 tetanised by make and break shocks through 

 one pair of electrodes, till ' exhaustion ' is 

 complete or nearly so, then sending the 

 tetanising shocks through another pair of 

 electrodes situated on different points of 

 the muscles gives again good tetanus. ' Ex- 

 haustion ' in consequence of electric tetani- 

 sation is, therefore, primarily polar, and the 

 results that have been supposed to demon- 

 strate the exhaustihility of motor nerve- 

 endings are readily reconcilable with the 

 ' discharge hypothesis,' local ' exhaustion ' 

 of the muscle substance immediately in 



