54 



SCIENCE. 



[N. S. Vol. XXIV. No. 602. 



the hearts with artificial solutions is attended 

 by contractions, while blood and its mixtures 

 produce no such effect; and (2) if two strips 

 of cat's ventricle, one cut so as to include a 

 considerable part of the anterior coronary 

 artery, and the other cut from the anterior 

 lateral margin of the right ventricle so as to 

 include no large vessels, be suspended and irri- 

 gated with the artificial solutions, the strip 

 containing the coronary artery soon exhibits 

 strong tonus upon which contractions may be 

 superposed, while a little later the other strip 

 begins to contract more or less irregularly and 

 without any change in tonus. It may be ob- 

 served in this connection that a strip of 

 thoracic aorta may exhibit a deportment simi- 

 lar to that of the ventricular strip containing 

 the coronary artery. 



From these observations we conclude that, 

 with hearts under the conditions of our 

 experiments: (1) It is highly improbable 

 that the production of a rhythmical beat is 

 dependent solely upon the constituents of any 

 one of the artificial solutions employed; that 

 these solutions alone are not sufficient to 

 initiate or sustain efficient beats of the heart. 

 It has been shown in this and other labora- 

 tories that such solutions are inadequate to 

 restore or even to sustain the activities of the 

 reflex nervous centers of mammals. We have 

 found the addition of a certain amount of 

 blood necessary to render these solutions effi- 

 cient. (2) For the production of the effi- 

 cient rhythmical beat of the isolated heart, 

 pressure or circulation of a suitable me- 

 dium in the coronary vessels is necessary. 

 Injection of blood or its dilutions into the 

 coronary veins is attended by much the same 

 phenomena as have been recorded for injec- 

 tions into the coronary artery, the principal 

 differences being the somewhat lower optimum 

 pressure and the lower pressure necessary for 

 the production of delirium cordis. The char- 

 acter of the beat may differ somewhat in the 

 two cases. As the pressure in the veins neces- 

 sary to produce rhythmical beats is in all 

 probability higher than that normally present, 

 the mechanism which initiates the normal 

 rhythmical beat must be sought elsewhere. In 

 further support of this view may be men- 



tioned the fact, as determined by inspection, 

 that, on injecting into the coronary artery, 

 the beat begins before much blood appears in 

 the coronary vein, although the beats are weak 

 before the complete establishment of the 

 coronary circulation. In suitable prepara- 

 tions, in which the rhythm is slow, the 

 coronary artery, or the tissue immediately sur- 

 rounding it, has been observed to pulsate, 

 and the beat to spread from the coronary ves- 

 sels over the heart. 



C. C. Guthrie, 

 F. H. Pike. 

 Hull Physiological Laboeatoet, 

 The Univeesity of Chicago, 

 May 25, 1906. 



^^OTES ON ORGANIC GHEMI8TBY. 

 esterification of tertiary and unsaturated 

 alcohols. 

 Not long ago there was given, in this 

 journal, an account of some recent improve- 

 ments in the methods of preparing esters.^ 

 Although these are of undoubted value, yet 

 the subject, as a whole, can not be said to be 

 in a very satisfactory state because there are 

 no methods, of general applicability, capable of 

 furnishing a good yield of the esters of. ter- 

 tiary and unsaturated alcohols. The primary 

 cause of the difficulty is the greater sensitive- 

 ness of these classes of alcohols, which results 

 in the production from them of other com- 

 pounds, such as unsaturated hydrocarbons or 

 tarry products, in relatively large quantity. 

 This behavior is further accentuated by the 

 fact that the velocity of their reaction and 

 their equilibrium points are both very low. 

 Whereas, in the case of propyl alcohol, if 46.5 

 per cent, is esterified in one hour and 66.8 per 

 cent, is esterified before equilibrium is at- 

 tained, these values become 26.5 and 60.5 per 

 cent., respectively, for secondary propyl al- 

 cohol, and for iertiaryhutjl alcohol, 1.5 and 6.6 

 per cent. The figures speak for themselves 

 and demonstrate how great, relatively, is the 

 opportunity for change to take place in the 

 tertiary alcohol by the action of the high 

 temperature or of the mineral acid or other 

 ' catalyst ' that may be present. 



'Science, XXIIL, 712 (1906). 



