460 



SCIENCE. 



[N. S. Vol,. XXV. No. 638 



conditioning influences that were obviously 

 influential in all our zymolytic experiments 

 were the character, state and strength of 

 the acid or base, the quality and concentra- 

 tion of the enzyme, the duration of the 

 period of digestion, the temperature of the 

 digestive mixture, and the nature of the 

 protein. No doubt the diflferent digestive 

 products themselves exerted unequal in- 

 fluences as the proteolytic transformation 

 proceeded. In experiments with fibrin and 

 elastin to determine the effects of the 

 zymolytic products of one of these pro- 

 teins on the peptic digestion of the other, 

 there was marked interference with the 

 peptolysis of one or the other (or both) 

 when samples of the two proteins were 

 together in 0.2 per cent. HCl in the pres- 

 ence of small proportions of pepsin. The 

 hydrogen ion is the favorable acid factor 

 in peptolysis. The associated anions or 

 molecules (or both) appear to interfere 

 (as a rule) with the peptic process, and 

 their divergent influences seem to account, 

 in part at least, for the quantitative dis- 

 parities noted in each digestive series of 

 our experiments. It has been shown in 

 our work, however, that acetic acid mole- 

 cules are practically without influence, 

 under ordinary conditions, on the peptol- 

 ysis of fibrin or elastin in solutions of 

 hydrochloric acid M/20—a. suggestion that 

 the purely chemical phases of the normal 

 gastric digestive process are practically un- 

 affected by vinegar in the proportions com- 

 monly ingested. The effects of acetic acid 

 and of vinegar on the secretory process in 

 the stomach will be investigated. In tryp- 

 tolysis the hydroxyl anion is the favorable 

 basic factor and the associated cations or 

 molecules (or both) seem to exercise the 

 deterrent influences. In general harmony 

 with the observed digestive disparities, 

 there were marked inequalities in the 

 swelling effects on fibrin in every equiva- 

 lent series of acid or basic solutions. 



Bloating influences on fibrin were due pri- 

 marily to the acid or base, but were more 

 pronounced in the presence of enzyme. 

 Elastin did not swell perceptibly in either 

 the acid or basic solutions employed, but 

 did so in the latter when trypsin was 

 present. In a given series of equivalent or 

 basic solutions under uniform digestive 

 conditions the degree and sequence of 

 zymolysis of fibrin were strikingly dif- 

 ferent from those of the digestion of elas- 

 tin. This fact necessitates the thorough 

 study of the zymolysis of many proteins in 

 samples of the same equivalent acid and 

 basic solutions. 



Putrefaction of Tendon, Collagen and Mu- 

 coid: D. E. RoELKET and Wm. J. Gms. 

 Unwashed tendon pieces undergo spon- 

 taneous putrefaction in distilled water, tap 

 water and 1 per cent, sodium chloride solu- 

 tions, under both aerobic and anaerobic con- 

 ditions. The coUaginous masses gradually 

 undergo complete disintegration, although 

 even after putrefaction has continued for 

 about two months in a liquid teeming with 

 motile bacteria, coUaginous fragments con- 

 taining unchanged fibers may be present. 

 The putrefactive odors are very marked. 

 Putrefaction at the end of the period 

 noted, and in the liquids used, has been 

 most advanced in the salt solution and 

 least advanced in the tap water. Anaerobic 

 conditions favored special velocity and ex- 

 tent of the changes. A study of the 

 products of, and the conditions best suited 

 for, the putrefaction of tendon is now 

 yielding numerous results. Similar ex- 

 periments have been begun with tendomu- 

 coid and tendocollagen. 



A Further Study of the Chemistry and 



Pharmacology of Ibervillea Sonar (bt 



Julia T. Emerson and Wm. H. Welkee. 



Some of the largest tubers of Ibervillea 



SonorcB were collected and an effort was 



made to ascertain their general chemical 



