Summary

Suggests an explanation for difference in excitability of Drosera leaves to meat and albumen on the one hand and, on the other, fibrin, areolar tissue, gelatin, and fibrous basis of bone.

Summary

Thanks for MS which he intends to read while on a week’s holiday.

Sends thanks for Francis Darwin’s offer of help and says that Francis’s experiments on digestion are complete.

Summary

Will prepare experiments with the fatty acids on digestion of gluten. Has found it is digested slowly, but entirely, with pepsin and hydrochloric acid.

Summary

Is delighted to hear that Pinguicula and Drosera digest fibrin. Suggests diluting gluten in weak hydrochloric acid to remove starch. Enamel was nearly digested [by Drosera] overnight. Would like to try separating the digestive ferment of Pinguicula.

Summary

Reports results of experiments comparing digestibility of gluten and fibrin for CD’s work on Drosera.

Summary

Sends results of experiments on digestion. Encloses two sets of notes: "Experiments on the digestibility of certain preparations sent by Mr Darwin" and "Note for Mr Darwin" [marked by CD for insertion in ch. 6 of Insectivorous plants].

Summary

Sends CD provisional information that artificial gastric juice dissolves bone entirely and that gluten and fibrin are completely dissolved in hydrochloric, propionic, and butyric acids. [See Insectivorous plants, pp. 118–19.]

Summary

Responds to CD’s questions about relation to gelatin of areolar tissue, fibrous basis of bone, and other substances CD is using in his work on digestion of Drosera.

Summary

Purpose of experiments was to determine digestive activity of liquids containing pepsin. Gives required amounts of hydrochloric, propionic, butyric and valerianic acids. Describes experiment and gives results. Also experimented on digestive activity of butyric acid at greater temperatures than the termperature of the body.

Summary

Sends cartilage from cat’s ear, the elastic fibres of which will probably resist digestion [by Drosera]. Is preparing fibro-cartilage, which he expects will be digested easily. [See Insectivorous plants, p. 104.]

Summary

A hasty answer to CD’s letter [8987] of 25 July. Mentions Dr Osler’s observations on behaviour of colourless blood corpuscles in solutions of sodium and potassium salts of same strength.