Exchanging further information on several aspects of the photographic process [see RH's 1840-4-15].

Has not lately done much work in photography, except to work with paper treated with vegetable substances.

Has received a request from the Admiralty to order a new telescope for the Cape observatory; at the same time, JH has received an unsolicited offer of a lens. JH seeks advice and information from GA.

Both JH and his wife, Margaret, are very concerned about the health of Madame Gerlach, the aunt of NS. Details are provided.

A letter of even greater urgency about the very serious state of health of Madame Gerlach, the aunt of NS [see JH's 1843-10-20]. Madame Gerlach is living with the Herschels [as tutor? or governess?].

RH's experiments are extremely interesting and deserve to be pursued. Comments on experiments made by Michael Faraday and others relating to the formation of crystals in a magnetic field and the effect such crystals have on polarized light.

As JH has not heard from NS, he has arranged for Madame Gerlach to stay with Mrs. Mason, now living in part of JH's former residence at Slough. But under no circumstances can Madame Gerlach return to her duties with JH's family.

Is submitting a list of corrections for the astronomy section of the Cabinet Cyclopedia. Proposes a major new work on astronomy.

Believes that rather than asking the government for more money to continue making magnetic observations, the six years of observations should be studied to see if further observations can be justified.

Replies to HF's 1845-1-12 that JH has no time to comment on HF's Britannic Censor.

Feels unable to become a member of the new society proposed by Halliwell, but wishes it well.

Will try to organize an international magnetic conference at the B.A.A.S. meeting in 1845, if GA agrees.

Having been assured by ES that the government might receive a request for more money for magnetic observations, JH retreats from his earlier position [see JH's 1844-7-17], and is willing to accept the possibility of a magnetic conference, which JH does not want to lead in any way. JH believes his scientific life is almost over and he has much to do.

Informs HL of the intention of holding a magnetic congress at the meeting of the B.A.A.S. in 1845, and JH seeks HL's opinion.

Has not received Tables A and B of the endowment tables. Comments on the use of these tables and would welcome his views on a possible alteration in policy.

Comments on JH's disagreement with the nebular hypothesis of Auguste Comte, and points out to JM that JH disagrees with some of JM's writings on physical science as well.

Proceeds to show JM in detail that Comte's nebular hypothesis is arguing in a 'vicious circle' [see JH's 1845-7-10].

Is willing to have JM show Comte JH's letter of 1845-7-13, but not JH's 1845-7-16. The latter of these two was intended to show JM the nature of the argument from JH's perspective.

Returns with many thanks E. C. Hawtrey's translations from Homer and Kallinos. Both are beautifully done. Comments on these and the meters suitable for English ears.

Sorry for the delay in response; JH has been ill for some time. JM has objected to P. S. Laplace's theory of probabilities; JH strongly supports Laplace.