92 Chittenden and Allen—Influence of various Salts 
Ferrous sulphate and Ferric chloride. 
The salts of iron, doubtless on account of their physiological 
importance and their great therapeutic value, have been experimented 
with by several observers. It has been a prevalent opinion that iron 
salts tend to produce disturbances in gastric digestion. Petit,* how- 
ever, states as a result of experiment, that preparations of iron, in 
small quantities, do not hinder the action of pepsin, but in large quan- 
tities they retard the action of the ferment, doing so according to 
Petit, by the hydrochloric acid of the gastric juice displacing the acid 
of the iron salt, thus forcing the pepsin to act with a less energetic 
acid. Diisterhoff,t dealing with the same question, came to the con- 
clusion that iron salts of the organic acids, exercise the greatest 
retarding effect on pepsin digestion, and moreover, that ferrous 
salts are better adapted to the organism than ferric salts. Diister- 
hoff also concludes that while the retarding action of iron salts is 
doubtless due, in part, to the setting-free of the acid of the iron salt 
by the acid of the gastric juice, there is in addition a specific action 
of the iron preparation of an unknown nature, prejudicial to digestion. 
Lastly, Bubnow { found that moist ferric hydroxide in small quanti- 
ties (not weighed) causes a scarcely recognizable diminution in pro- 
teolytic action, while the presence of 1 per cent. of ferrous chloride 
and ferrous sulphate causes marked retardation, as does also an 
excess of ferric hydroxide. The most intense action was observed on 
the addition of 5 per cent. of ferrous sulphate. No quantitative 
results, that is, percentages of albumin digested were, however, 
obtained. 
Our experiments were made only with crystallized ferrous sulphate 
and ferric chloride. It appears superfluous to try the action of ferric 
hydroxide, which must necessarily, if in sufficient quantity, neutralize 
the acid of the gastric juice and thus prevent digestion by with- 
drawal of the free acid. 
* Quoted by Bubnow in Zeitschrift fiir physiologische Chemie, vol. vii, p. 316; also 
abstract by Herter in Jahresbericht fiir Thierchemie, 1880, p. 309. 
+ Ueber den Einfluss von Kisenpraparaten auf die Magenverdauung. Jahresbericht 
fiir Thierchemie, 1882, p. 257. 
¢ Ueber den Einfluss des Hisenoxyhydrats und der Hisenoxydulsalze auf kiinstliche 
Magenverdauung und Faulniss mit Pancreas. Zeitschrift fiir Physiologische Chemie, 
vol. vii, p. 315. 
