Thanks for lectures on heat motion theory and radiation through earth's atmosphere, and for brochure on 'conformation' of the Alps. Asks about upcoming lecture of JH's son [Alexander].

Remarks on upcoming lecture of JH's son [Alexander], and on glacial movement.

Thanks for a gift.

Thanks for and comments on papers on scientific history and molecular physics, particularly on a magnetic experiment and on dynamical efficiency of coal relative to motion theory of light and heat. Comments on nature of heat, 'vis viva.' Deplores laxity with which physicists use and confuse terms 'force,' 'motion,' and 'energy.'

Regrets 'stupidity' of Italian post office, which lost note sent to JH suggesting reprinting of passage from Treatise Astr. of 1833 on operations of sun in second edition of JT's book. Also wants to publish JT's 'extremely philosophical views' on muscle contraction.

Thanks for and comments on paper on luminous and obscure radiation, particularly on extra spectral rays, incandescence of platinum, and experiment using transcalescence of iodine.

Is not 'at liberty' to speak of experiments on change of refrangibility of 'extra-red' rays. Discusses other experiments on extra-red regions, having used various prisms but not obtaining JH's results.

Surprised that JT cannot obtain heat spots [see JT's 1864-11-14]. Describes glasses and lenses used.

JT does not have 'luxury' of using sunshine; uses electric light. Perhaps this adds to inability to obtain heat spots [see JH's 1864-11-16].

Asks JH to be a shareholder in venture to publish new weekly scientific journal.

Wishes luck but expresses inability to help with new science journal [see JT's 1864-11-18].

Sends copy of JT's '3rd Memoir,' along with specimens of liquid mercury ethyl and mercury methyl from discoverers Edward Frankland and B. F. Duppa.

Corrects misinformation about refraction and dispersion of mercury ethyl and mercury methyl.

Describes experiment involving viewing spectrum of a light flash as it advances and recedes. [Marked 'not sent on further consideration.']

Comments on excellence of the lecture at the Royal Institution of JH's son [Alexander].

Thanks for note [see JT's 1866-5-26] on improvement of the lecturing style of JH's son [Alexander]. JH's son has studied lecture's subject deeply and loves science; JH hopes will be physics professor at a 'considerable institution.'

Asks whether Michael Faraday's work with glass resulted in improved manufacturing or if rather its main scientific value was in discovery of diamagnetism.

Believes Michael Faraday's boro-silicate of lead has not been used for telescopes, but JH and others have tried using it for other optical purposes. Describes method for producing veinless flint glass.

JT has suggested that JH's son [Alexander] be appointed to position in Royal School of Mines, but colleagues, unwisely, JT thinks, want someone more well-known.

Thanks for paper on action of solar and electric light on vapors, which should give JT further insight into blue color of sky and polarization of skylight. Comments on the latter. JH's son [Alexander] is working hard at Glasgow.