30 



Scientific Proceedings (117). 



being necessary. This figure is taken as a basis for the tissue 

 work. The writers are unable to determine any factor in the 

 tissue which may prolong the period of reaching equilibrium and 

 while it is possible to explain the results obtained, as having to 

 do with inequilibrium, the burden of proof is rather upon this 

 aspect of the question, for one must show why liver tissue should 

 demand more time for reaching equilibrium than the buffers. 



The protocols following are those of two experiments. A third 

 was conducted with practically identical results: 



The results are striking, the reaction of the tissue being de- 

 cidedly acid at the first reading, taken within five minutes after 

 the time of excision of the liver. Then there is a slow fall to 

 neutrality, which is reached within about 45 minutes. A rise 

 ensues, which continues for a considerable length of time, over 24 

 hours at least. 



The meaning of these findings is not clear, but they may be due 

 to the fact that acid is produced at first in an explosive way, a con- 

 clusion which is justified by the studies of Fletcher, 1 who found 

 that one fifth of the CO2 produced by an excised muscle arose in 

 the earliest stages; by the studies of Fletcher and Hopkins, 2 who 

 found, always, in dying tissues lactic acid; and by the investiga- 

 tions of Foster and Moyle, 3 who found 0.218 per cent, lactic acid 

 developed in injured muscle (minced) as compared to uninjured 

 muscle 12 days at o° C, 0.017 per cent. Secondly, the buffer 

 action of the proteins, etc., in the tissue may exert its effect, caus- 

 ing a "fixing" of the free acid, but finally this effect is nullified by 

 a saturation of the buffers and a rise in free acid begins. 



If these results are free from criticism, a more substantial basis 

 for the conception of how autolysis proceeds is available. Bradley 

 showed in his first series of studies that the proteins of the sub- 

 strate in autolysis became altered in some way whereby they be- 

 came more digestible in tissue hydrolysis under the influence of 

 the tissue protease and Dernby virtually substantiates these 

 findings. The older work of Dochez, of Hedin and of Rowland 

 point to this conclusion and the interpretation of relation of reac- 

 tion to substrate is in keeping with the recent studies of Northrup, 



1 Fletcher, W. M., J. Physiol., 1902, xxviii, 354. 



1 Fletcher, W. M., and Hopkins. F. G., /. Physiol., 1907, xxxv, 247. 



» loc. cit. 



