June 9, 1905.] 



SCIENCE. 



887 



lose in the order given above. The con- 

 stants were taken from the formula: 

 TOO 



Cu acetate • • v — 



^- = Z 



100 



('. acetic acid • - ^- 



/' 



where v is the dilution, a the percentage of 

 copper hydrate at 100° C, and /? the per- 

 centage of ionized acetic acid. The follow- 

 ing values of K were obtained : 



Leviilose 0.0'276 



Galactose 0.0185 



Glucose 0.0176 



Maltose 0.0096 



Lactose 0.0078 



If we determine K for Barfoed's reagent 

 in the same way, considering that in the 

 use of it we would dilute it about one half, 

 we get 0.0130. This places it between the 

 mono- and disaccharides, where it should 

 be theoretically. 



Artificial Production of Heart Rhythm: 

 David J. Lingle. 



Physiologists believe rhythmic activity 

 can be revived in heart muscle by electrical, 

 mechanical and chemical agencies. These 

 ideas are based on work done by experi- 

 menters who ignored the role of salt solu- 

 tions in producing rhythms and used a 

 sodium chloride solution to hold or moisten 

 a heart strip when testing the power of an 

 agent to make it beat. As a sodium chlo- 

 ride solution of itself has this power, a re- 

 sult obtained under these conditions is un- 

 satisfactory because the agent tested has 

 been made to act with another capable of 

 producing the result. 



The inference, from work of this kind, 

 that a constant current is a rhythm pro- 

 ducer, is not correct. Because when the 

 same constant current is made to pass 

 through two similar strips from the same 

 heart, one in a moist chamber, the other in 

 air, a rhythm appears only in the latter, 

 which is moistened with NaCl solution, to 



prevent drying. The other strip with the 

 same current, but without the NaCl solu- 

 tion, remains quiet. (In this experiment 

 the non-polarizable electrodes should be 

 moistened with LiCl solution, otherwise 

 they may hold enough NaCl to start a 

 rhythm. ) 



The same is true of strips treated with 

 induction shocks, either slowly repeated or 

 tetanizing. With a NaCl solution they 

 start rhythms, but without it they do not. 

 IMechanical tension, either constant or in- 

 termittent, will cause rhythms if the sus- 

 pended strips are moistened with a NaCl 

 solution, but it fails without this. It would 

 seem, then, that the rhythm-producing 

 power of electrical and mechanical agents 

 of this kind is due entirely to the NaCl 

 solution used along with them. 



No work along this line has been done to 

 test the powers of the various chemical 

 agents. But as most of these have been 

 used with a solution of NaCl, it will be 

 found, in all probability, that they are not 

 exceptions. Most of them are simply com- 

 pounds that do not interfere with the ac- 

 tion of the NaCl used with them, rather 

 than real rhythm producers. 



Experiments on Resuscitation: C. C. 



Guthrie and G. N. Stewart. 



Kuliabko's work on resuscitation of the 

 excised mammalian heart after a long in- 

 terval led us to undertake resuscitation 

 experiments in entire animals. These were 

 begun in the autumn of 1902. 



After five to fifteen minutes' complete 

 stoppage of the heart (determined by in- 

 spection) by asphyxia, drowning, ether, 

 chloroform or electrical currents, in many 

 cases an efficient circulation was reestab- 

 lished. A combination of artificial respi- 

 ration, heart massage, occlusion of the 

 aorta and arterial injection of defibrinated 

 blood gave the best results. 



Disappearance of the pulse as deter- 



