886 



SCIENCE. 



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



stretched and the relaxed nerve or nerve- 

 cord. The increase in the transmission- 

 time shows that the stretching is not merely 

 a straightening ont of kinks or folds in the 

 nerve-fibers. The conducting substance 

 mnst be actually extended. But this ex- 

 tension of the conducting substance is ef- 

 fected without inducing any changes of 

 stress or tension in it, because the process 

 (nervous impulse) conducted by it is not 

 altered. Siich an extension of conducting 

 substance can be effected only in case it is 

 in a fluid condition. 



The Antagonistic Action of Calcium to 

 Barium, and of Calcium and Barium to 

 Veratrin, on the Mammalian Heart: S. 

 A. Matthews. 



Calcium salts and barium salts show the 

 same antagonism as regards the mammalian 

 heart as Sydney Ringer observed on the 

 heart of the frog. Further, both calcium 

 and barium are antagonistic to veratrin. 

 Barium shows a greater antagonism to 

 veratrin than calcium, but owing to the 

 marked poisonous properties of barium in 

 sufficient doses to counteract the veratrin 

 effects, calcium is necessary to check in 

 part the barium effects, and the antago- 

 nism to veratrin is more complete if a solu- 

 tion of m/2,000 BaClj made up in an m/8 

 CaClo solution be injected. This also cor- 

 roborates Ringer's results on the frog's 

 heart. 



Determination of Freezing Point of Small 

 Quantities of Liquid, Especially for 

 Clinical Purposes: T. M. Wilson. 

 Dr. G. N. Stewart suggested that it 

 would be worth while to investigate 

 whether by using a small tube and adding 

 to a small quantity of a solution whose 

 freezing point was to be determined a 

 quantity of a liquid which does not exert 

 osmotic pressure (clean mercury, e. g.) suf- 



ficiently large to insure complete immer.sion 

 of the thermometer bulb, fairly satisfactory 

 readings might not be obtained. By per- 

 forming all the manipulations in a definite 

 way, and, in particular, keeping the degree 

 of undercooling about the same in succes- 

 sive observations, it was found that this 

 was the case. Comparison of the results 

 obtained on a standard salt solution by this 

 method and by the ordinary method showed 

 that readings reliable to the hundredth of a 

 degree centigrade could be got with as little 

 as 0.3 c.c. of solution. The determinations 

 are, of course, less accurate than those 

 inade wdth 10 or 15 c.c, but the method 

 will, it is hoped, permit the approximate 

 measurement of the freezing point of such 

 quantities of blood or serum or of the rarer 

 animal liquids as are easily available for 

 clinical purposes, without diluting with 

 water or salt solution, a procedure to which 

 there are weighty objections. 



Preliminary Report on an Attempt to De- 

 termine the Oxidizing Coefficients of Dif- 

 ferent Tissues: H. McGuigan. 

 The tissues of the body are known to 

 differ in their oxidizing powers. The at- 

 tempt was made to express the comparative 

 oxidizing powers of the more common 

 sugars in terms of electro-chemical units, 

 with the hope of getting data from which 

 to compute the voltage necessary to relieve 

 the enzymes of their charges and thus in- 

 directly obtain their oxidizing powers (see 

 A. P. Mathews, Am. Jour. Physiol., Vol. 

 X., p. 450). Comparative figures were ob- 

 tained for lactose, maltose, glucose, galac- 

 tose and levulose. 



Neutral copper acetate will oxidize all of 

 the above sugars in the order given, lactose 

 being the most difficult. The addition of 

 know^n quantities of acetic acid will pre- 

 vent the oxidation. The volume of the 

 acid sufficient to do this differs for each of 

 the sugars, increasing from lactose to levu- 



