To Daniel Oliver 12 [October 1860]1
15 Marine Parade | Eastbourne
My dear Sir
The Drosera & leaves of Dionæa. arrived quite safe. I am very much interested by them.— Pray give my best thanks to Sir William, & accept them yourself.—2
I am very busy & get my constant enemy headach; so will not write any more, but I have got a good deal to say first day I can.
Will you try one easy experiment.— Drop on sensitive hair of Dionæa one drop gently of pure water; & get solution of Carbonate of Ammonia 6 six gr. to 2 two oz of distilled water, & drop this & see if it immediately or within hour or two causes movement. This will not injure leaf.— Perhaps safer to get 4 gr to 2 oz water3 Also one drop of the C. of Ammonia on disc of leaf.— I want so much to know whether movement analogous of Dionæa & Drosera.—4
Yours very truly | C. Darwin
Requests DO apply carbonate of ammonia to sensitive hair of Dionaea and measure reaction time. Wants to compare Drosera and Dionaea.