Has been pursuing his magnetic experiments with crystals and will be publishing a memoir on them. Comments on these experiment. Is there a difference in the mass of the earth at the poles?

Is giving a series of lectures at the Collegiate Institution. Has made some interesting discoveries recently and has deposited a paper with Faraday for communication to the R.S.L. Comes to the conclusion that chemical action can be suspended by magnetic force. Comments on this.

Has often thought of the inactive condition of iron and has made some notes before he received JH's comments. Has overcome all JH's objections to the intrinsic difference in the two poles. Comments on some of these experiments.

Regarding Benjamin Peirce's Elementary Treatise on Sound. Can lend him his own copy if JH has no copy.

Has sent the book. Gives an outline of his own work and ideas he has for the improvement of the piano. Would like JH's comments.

Thanks for his kind letter. Congratulations on another addition to his family.

Hopes all his family are well. If JH proposes to attend the Trustees meeting of the British Museum on Saturday, will he breakfast with RI and Dr. T. R. Robinson of Armagh?

Is applying for the French Mastership at the Belfast Academy and would be pleased to receive a testimonial from JH. Is also inviting subscribers for a new work to be published later.

Has been carrying out a series of experiments with spiders immersed in acids and finds their bodies are not protected in any way. Has also been experimenting with elastic tissues to see if there is a change of temperature.

Has seen the seventh satellite of Saturn. Encloses diagrams and comments on them.

Was in error when in his last letter he stated he had seen the seventh satellite of Saturn; he has yet to see it.

Details of WL's observations of the seventh satellite of Saturn.

Details of WL's observations of a ring and satellite of U. J. J. Leverrier's planet.

François Arago has communicated JH's letter informing him that UL has been awarded the Copley Medal.

Is pleased with the arrangements for the forwarding of his medal. Is sending for the R.S.L. five examples of his researches.

Did not realize his question would require so much of JH's valuable time to answer. Hopes to introduce some safe German Philosophy into the appropriate departments at Trinity College. Will look into the Lehrbuch.

Received his letter enclosing Edward Sabine's a few days ago on returning home. Busy at College; otherwise would have written. Could have attended a meeting of Committee of Physics had he known. Discovery of the new planet is a triumph. Has he heard of the attempt to destroy the telescope of William Parsons (3rd Earl of Rosse)?

When he received JH's request to give a lecture on American geology he did not treat it seriously. Now R. I. Murchison has made a similar request so thinks he could work up a popular lecture on the Mississippi Delta. Will keep off his old ground.

H. C. Oerstedt has been elected to the Society to replace F. W. Bessel, who has died. The Society is lacking one part of the Memoirs of the R.A.S.

Has been on the Continent, which accounts for the delay replying to JH's letter of June. Regrets he cannot give an answer to JH's queries regarding the constitution of the ether. Fears his hypothesis on the density of the ether is not clear as it has misled JH. Has read Michael Faraday's papers with eagerness.