hydrochloric acid is not absolutely indispensable for fairly vigorous proteolytic action, and that in the presence of moderate amounts of proteid matter a large quantity of acid is required to even saturate the albuminous material. [112] Virchow’s Archiv, Band 128, p. 408. Consider for a moment the amount of acid a given weight of proteid will combine with, before a reaction for free acid can be obtained. Thus, Blum[113] has stated that 100 grammes of dry fibrin will require 9.1 litres of 0.1 per cent. hydrochloric acid to completely saturate it. Hence, with a daily consumption of 100 grammes of proteid, there would be needed for gastric digestion 4.5 litres of 0.2 per cent. hydrochloric acid daily, and even this would not suffice to give any free acid, assuming that none of the acid is used over again. The results I have already given for egg-albumin tend to show that 1 gramme of pure albumin, free from inorganic salts, when dissolved in a moderate amount of water will combine with about 30 c.c. of 0.2 per cent. hydrochloric acid. Consequently, on this basis, 100 grammes of dry egg-albumin will combine with 3 litres of 0.2 per cent. HCl, and not until this amount of acid has been added to such a mixture will reaction for free acid be obtained with Günzburg’s reagent. Hence we can easily see, in view of these figures, that the production of hydrochloric acid by the gastric glands may at times be very extensive, without the stomach-contents necessarily containing free acid. [113] Zeitschr. f. klin. Medicin, Band 21, p. 558.