Says JH will not join the society to which he has been invited, because he has done nothing on the subject for a long time and JH's attendance would not be productive. Thanks for some lectures and papers sent to him.
Says JH will not join the society to which he has been invited, because he has done nothing on the subject for a long time and JH's attendance would not be productive. Thanks for some lectures and papers sent to him.
Inquires whether Charles Wheatstone ever fulfilled his intention to carry out experiments to measure the speed of light in the atmosphere by means of 'revolving machinery.'
Thanks for the paper on the photographic effect of light on drugs. JH also comments on the photographic experiments of Mary Somerville.
Thanks RH for the papers of researches on light just received.
JH sends some examples of a unique kind of latent photograph, and adds other comments about various aspects of photography. JH has seen a good aurora. He now agrees with A. C. Becquerel's theory of the spectrum.
Letter writing has been delayed by the crush of other business. Comments on names for various aspects of heat, light, color, and phlogiston. JH describes the actions in his 'amphitype' process. Is looking forward to RH's forthcoming work on photography.
Does not think that RH would be satisfied with the position of Assistant Secretary of the R.S.L., as it is largely clerical, and would not allow much time for chemical or photographical experiments. JH is not aware whether there is a position available at the Royal Institution, but would be willing to speak to Michael Faraday.
Cannot provide any specimens of photography or the spectrum good enough for an exhibition, as most have faded. A French chemist just announced as a discovery a fact long since known by JH.
Comments on different washes to be used in photography, and clarifies the matter of a supposed Daguerreotype of the nebula in Orion.
Has no photographs with him and when next JH goes to Collingwood, he will look to see if there are any left.
Doubts that there is any significant difference of density between the northern and southern hemisphere.
Thanks for the 'exquisite specimen of Daguerreotype.' Speculates on the possibility of making Daguerreotype portraits small enough to be set in rings or in shirt pins.