Add MS 88942/1/191

This notebook contains various notes on a wide range of subjects. Mathematical notes towards the end of the notebook, headed 'at Nice, Nov. 17', deal with conic sections, eccentricities, hyperbolas, and the multiplication of integrals (one entry is dated 'Feb. 16 1834'), long notes on definite and indefinite integrales, 'On fragmentary curves', and trigonometric functions, geometric series, integral theorems, on 'reciprocal limits', and discontinuous functions. Further miscellanous notes deal with the camera lucida applied to the eyeglass of a telescope to examine lines in a spectrum, on an experiment at the Royal Institution on electricity (see Philosophical Transactions of the Royal Society of London 1759 (51) 317, pp. 5-13), a solution which turns from blue to clear over months, and which can be used as ink to write letters which disappear but remain visible in relief, more notes on invisible ink. Talbot mentions that Faraday informed him of another way to create invisible ink (see also Add MS 88942/1/190 and Add MS 88942/1/193). This entry is followed by some notes on the mixing of colours and how they change (Talbot tested this in this notebook, using different types of ink). Further notes contain entries on optics and electric sparks, entries on blue vitriol wetted and fastened to a plate glass on either side, making a blue glass, on making a resin prism, and on colour blending. There are also notes on a revolving circle experiment (a modification to Wheatstone’s experiment on the velocity of electricity, later published in Charles Wheatstone, 'An Account of Some Experiments to Measure the Velocity of Electricity and the Duration of Electric Light', Philosophical Transactions of the Royal Society of London 124, pp. 583-591). Talbot had attended Faraday’s and Wheatstone’s presentations on this ongoing work in 1833 at the Royal Institution. Talbot published this proposal as part of his 1833 paper 'Proposed Philosophical Experiments', Philosophical Magazine, ser. 3, vol.3 (14), pp. 81–82. Wheatstone became upset at Talbot for pre-empting his work before he had chance to publish. Further notes comprise entries on capillary tubes, a paragraph on passing a spectrum through prism through cobalt glass, on making transparent compounds, on producing green liquid by mixing copper suplhate solution with common salt, notes on mirrors an triangular prisms, a few lines on a method for measuring 'the least distance of distinct vision', on crystallization from different solutions, a note on making a compound prism, notes on a telescope stand, and notes observing 'the spectrum of a narrow aperture' with a teleoscope. Talbot suggests that using a camera lucida 'applied to the eyeglass of a telescope' would be useful for examining lines in the spectrum by projecting it upon a horizontal sheet with a scale written on it. There are also notes on the trapezoidal piece of glass such as in a camera lucida followed by a simple geometrical proof about the images of an object obtained in two mirrors at an angle with each other as in a camera lucida including a comment with the angles between mirrors in his camera lucida, followed by 'expts with a blue cobalt glass of variable thickness, & slightly prismatic'. The notebook also includes the first mention of optically fixing moving objects, on 'oxygen blowpipe', on colours of liquid solutions, on 'Brande’s lecture at R. Instn.', on the detonation of nitrogen compounds, on 'Arrangement for Combined Prisms', and on a 'Singular microscope'. Talbot notes a peculiarity in his microscope where the second surface of the lens acts as a mirror so one can see dust on the upper surface of the eyeglass reflected in the eyepiece magnified. He also mentions this observation on two glasses cemented together (and the double images seen). Further notes refer to the Royal Institution and to Faraday, to lime and carbonic acid uniting only in the presence of water, and chemical notes regarding gases, starting with the heading 'liquefaction of gases'. Talbot also made some tetrahedron-shaped crystals, which he showed to Faraday, who assumed they were protomuriate of copper. Talbot, however, believed them to also contain tin. There are more details on these experiments and on chemical experiments, notes on 'Faraday at R. Instn. Ice conducts heat, water not.', on 'a piece of Icelandspar, bought of Watkins & Hill, giving many images', notes on the manipulation of these images, notes on experiments with polarized light and notes on various materials which can 'restore the light', more on depolarizing, and notes on a concave mirror 'giving 4 reflections of a candle of difference sizes'.

Notebook started: 5 May 1832, London. Designated 'J' on outside and inside front cover.