CD may be interested in a reference to a method of detecting 1/195000 of a grain of sodium chloride.

Also, on Drosera, suggests it would be interesting to try substances such as gun-cotton, in which nitrogen is in very different states from a salt of ammonia.

Asks him to thank A. S. Taylor for note.

Describes experiments on Drosera.

Discusses reviews of the Origin. By far the best is by Asa Gray.

Discusses plans for new edition of Origin.

Thanks for railway map.

Surprised about Richard Owen: "I thought his courage was as indomitable as his malignity."

Sends extract [Sir John Herschel, "Physical geography", from the Encyclopaedia Britannica (1861)].

Obliged for the Theophrastus. Will return it.

Son [Leonard] ill with scarlet fever. Also Mrs Darwin.

Intends to give up work on Drosera until Variation is done.

Thanks for maps.

George [Darwin] failed at St John’s [College, Cambridge] and will stay another year at school.

May his son George call for advice on his career?

CD has been ill for past four months.

Discusses income provided for sons at Cambridge.

Thanks for note about George Darwin’s gaining Second Wrangler.