Carbon Dioxide of Injury in Nervous Tissue. 35 



pound but reverses this relation notably in the acetic-glycocoll 

 couple and in the propionic-alanin pair. 



3. The agar-protein biocolloid shows notably greater hydration 

 in the amino-acids than in the related organic acids, and greater 

 even than the hydration in distilled water. 



4. Equimolecular concentrations of amino-acids produce 

 notably greater swellings of the biocolloids in comparison with 

 related organic acids implying the positive action of factors other 

 than the hydrogen ion concentration. 



5. Glycocoll facilitates hydration in all concentrations above 

 .01 M. in both agar and agar-proteins, and also in agar-gelatine, 

 the data of which are not given in this paper. This fact goes far 

 in explanation of the scattered results obtained by various workers 

 in which accelerated growth or increased total growth has been 

 seen to result from the addition of glycocoll to nutrient solutions. 

 Such increases have been attributed to catalytic action by Dakin 

 and others. 



6. The amide, asparagin, induces a maximum hydration, 

 greater even than that possible in agar in distilled water, and very 

 high at all concentrations. Similar action was exerted on agar- 

 gelatine and agar-protein plates. The positive action of both 

 glycocoll and asparagin is indicated by the fact that the maximum 

 effect is reached at certain concentrations above the minimum. 



The destruction of our supply of phenyl-alanin in transit pre- 

 vented an examination of the effects of this substance, but it will 

 be possible to extend this work to this and other amides in the 

 next few months. 



22 (1397) 



The carbon dioxide of injury and of respiration in nervous tissue. 



By A. R. Moore. 



[From the Physiological Laboratory of Rutgers College, 

 New Brunswick, N. J.] 



It has been shown that injured nervous tissue gives an acid 

 reaction with phenolsulphonephthalein as indicator and that the 

 acid measured by Haas 1 method is carbon dioxide. 2 If the rate 



1 Haas, A. R. C, Science, N.S., vol. 44, pp. 105-108, 1916. 



2 Moore, A. R., Proc. Soc. Exp. Biol, and Med., vol. 15, pp. 18-19, I 9i7- 



