322 JOURNAL OF THE WASHINGTON ACADEMY OP SCIENCES VOL. 11, NO. 14 



to write such a reaction is carbon monoxide poisoning. In this 

 intoxication the carbon monoxide gas unites in fixed proportions with 

 the hemoglobin of the blood to form a very stable combination which 

 is incapable of transporting oxygen from the lungs to the tissues. 

 The result is asphyxiation, but even in this case we are not helped 

 much by our ability to write this equation, for it tells us nothing about 

 the processes that take place during asphyxia. Indeed, we know 

 very little about them. Carbon monoxide is the cause of death. 

 The more immediate cause, however, is oxygen starvation, and if we 

 are very exacting, we must demand the equations of asphyxia. These, 

 however, we are quite unable to give. 



Of recent years very different conceptions have been developed. 

 The older men, dominated by the imagery of organic chemistry, 

 sought the chemical reactions underlying the phenomena of pharma- 

 cological action, thinking that they are ordinary stoichiometric re- 

 actions, very complex ones if you will, but still of the ordinary type 

 and, therefore, dependent upon the chemical properties of the sub- 

 stances taking part in them. In those days the prevailing conception 

 of protoplasm was that it consisted of huge, very complex, very un- 

 stable molecules. The various parts of such a live molecule were 

 believed to have different functions. According to this conception, 

 the live molecule might have been pictured as resembling a chestnut 

 burr bristling with prickles or grappling hooks each capable of grappling 

 a specific and different food substance.^ Some of the poisons were 

 supposed to be anchored by such grappling hooks just like foodstuffs 

 and the specific action of a given substance upon a given cell or tissue 

 was supposed to be due to the fact that that substance had some in- 

 herent property that caused it to be anchored by some specific grappling 

 hook in that cell. Therefore, explanation of the physiological action 

 of a substance was sought primarily in the structure of its molecules 

 rather than in its physical properties. To some particular grouping 

 of the atoms in the molecule solely was attributed the physiological 

 action of the substance.* Such a group was spoken of as the carrier 

 of the action, and much was written about "toxophore" groups, 



• P. Ehrlich. On immunity with special reference to cell life. Croonian Lecture. Proc. 

 Roy. Soc. London 66: 432-437, 446. 



*0. LoEW. Einnaturliches System derGiftwirkun gen. (Stuttgart, 1893.) P. Ehrlich. 

 Ueber die Beziehungen von chemischer Constitution und pharmakologischer Wirkung. Vortrag 

 gehalten im Verein fur Innere Medicin am 12 December, 1898. v. Leyden Festschrift p. 

 647. (August Hirschwald, Berlin, 1902.) 



