TOXICOLOGY AND PHARMACOLOGY 385 



take up much more than its own volume of oxygen. Since it has 

 some other properties of hemoglobin H. W. FISCHER calls this prepa- 

 ration " synthetic active hemoglobin" (Effectsynthese des Hdmo- 

 globins). Properly prepared ferric oxid may be injected intravenously 

 into rabbits; yet depending upon how it was prepared it proved to 

 be more or less toxic even though no embolism could be discovered. 

 Negative ferric oxid seems to store itself up in the glandular organs 

 (liver, kidneys) just as do other hydrophobe, mostly negative col- 

 loids. No change of charge occurs since it is only after HC1 is added 

 that a blue coloration occurs with potassium ferrocyanid. Although 

 positive ferric oxid hydrosol strongly adsorbs arsenious acid, its 

 protective action is almost completely lost if such a mixture of the 

 ferric oxid hydrosol and the adsorbed arsenious acid is injected 

 subcutaneously. Negative ferric oxid hydrosol, under the same 

 circumstances, exerts a very considerable protective action, but fails 

 completely when such a mixture is injected intravenously. H. W. 

 FISCHER attributes this to the presence of hemoglobin which tears 

 the arsenious acid from the ferric oxid hydrosol. 



Narcotics and Anesthetics. 



We class as narcotics such substances as temporarily suspend 

 cerebral function, and the activity of the reflex centers. Narcosis is, 

 therefore, a reversible process. 



According to the theory of HANS MEYER and E. OVERTON, nar- 

 cosis is produced by such substances as dissolve especially easily in 

 the lipoids of the plasma pellicle but are not entirely insoluble in 

 the plasma. 1 They determined the distribution coefficient between 

 oil and water for a large number of substances and found that those 

 substances in which the distribution coefficient (oil : water) is high 

 are good narcotics, e.g., chloroform, ether, acetone, chloral hydrate, 

 urethan, etc. The coincidence is not only qualitative but it was 

 possible by determining the " critical concentration" to show that it 

 was quantitative. By "critical concentration" i meant the con- 

 centration of a narcotic in water which just suffices to maintain the 

 narcosis of an organism (animal or plant). With over 100 substances, 

 a surprising parallelism was shown to exist between "critical narcotic 

 concentration" and coefficient of diffusion between oil and water, so 

 that a causative connection between narcosis and fat solubility 

 seems obvious. 



1 There exists a certain parallelism between the physiological action of nar- 

 cotics and their ability to depress the surface tension of water. Upon this is 

 based J. TRAUBE'S * theory of narcosis. The depression of surface tension favors 

 the penetration of the narcotic into the cell. 



