CARBON DIOXIDE AS A NARCOTIC AGENT. 463 



in sea water practically saturated with carbon dioxide are readily 

 reversible up to exposures of twenty minutes. Beyond that point 

 abnormalities may appear, though after exposures of two and one 

 half hours 95 to 100 per cent, of the eggs ultimately divide. 



4. The after effects of exposures of moderate length to carbon 

 dioxide are comparatively slight, the delay in the first cleavage 

 being only a little greater than the actual time of exposure. 

 Mathematically, the relation 



y = a-\- i.iS^r 



(where a = normal cleavage time; .r = =time of exposure; and y 

 cleavage time of the exposed eggs) has been found to describe 

 fairly accurately the results obtained at 21.4 ( i.) with sea 

 water from 30 per cent, saturation to almost complete saturation. 



I am glad to have this opportunity to express my gratitude to 

 Dr. M. H. Jacobs for his suggestion of this problem and for his 

 continued interest in the progress of the work. 



BIBLIOGRAPHY. 



1. Beddoes, T., and Watt, J. 



1796 Considerations on the Medicinal Use, and on the Production of 

 Factitious Airs. Bristol. 



2. Brooks, S. C. 



'18 Journ. Gen. Physiol., I, 61. 



3. Cohn, E. J. 



'18 BIOL. BULL., XXXIV., 167. 



4. Dastre, A. 



'90 Les Anesthesiques. Paris. 



5. Follin, E. 



'56 Arch. Gener. de Mtd. (Series V.), VIII., 608. 



6. Grehant 



'87 Compt. Rend. Soc. Biol., IV., 52. 



7. Harvey, E. B. 



'27 BIOL. BULL., LIL, 147. 



8. Herpin, J. C. 



'64 De L'Acide Carbonique. Paris. 



9. Kidd, F. 



'14 Proc. Roy. Soc., Series B, LXXXVII., 408, 609. 



10. Loeb, J., and Northrop, J. H. 



'17 Journ. Biol. Chem., XXXII., 103. 



11. Ozanam, C. 



'58 Compt. Rend, de 1'Acad. des Sci., XLVI., 417. 



