31 Sackville St London <1>
July 25. 1841
Dear Sir
I do not know whether you are aware that the new fact in Chemistry which interested you so much, the conversion of Carbon into Silicon, has now been published by its discoverer Dr Samuel Brown, <2> in the Transns of the Royal Society of Edinburgh (vol. XV part 1). The memoir is highly interesting, and though I am not Chemist enough to form a decided opinion on so difficult a subject, yet I think he makes out a prima facie case, which calls for investigation. The experiments are fully detailed & are such as may be repeated in any laboratory – In one experiment, from 30 parts of ferro-cyanate of potash<3> he extracts 5 of silicic acid.
In another, he converts the ferro-cyanate into a substance resembling white sand, consisting of small octohedral crystals of silicate of iron. He also states that part of the iron is in this operation converted into something which is either rhodium or a new metal. It has lost all the properties of iron, being insoluble in acids. I shall be very glad to hear what is your opinion of these experiments and conclusions, which threaten to make short work with all existing chemical theories.
Davy <4> had an evident leaning towards the hypothesis of the elements (so called) being in fact only modifications of each other, and I find that the respectable name of Schönbein <5> is to be added to the list of those who patronize the idea – By the way what do you think of the new element Ozone which Schönbein thinks he has discovered, & which is either formed or developed or set free by electric sparks passing thro’ air, & is the cause of the peculiar odour perceived. An experimenter who has collected great quantities of atmospheric electricity, by stretching wires over the town of Sandwich, vouches also for this Ozone, which he says he has collected in abundance.
I don’t know whether you have tried my Calotype process, if so I hope you may have met with success. We find that portraits may in general be taken in about a minute in ordinary daylight, but we are attempting further improvement. Daguerre has rather mismanaged the communication to the Academy of his last discovery. He sent a verbal message by Arago, who misunderstood it, & stated it to consist in electrifying an iodized plate. <6> Now D. says this was all a mistake, & that the plate is to be not iodized but acidulated. <7> Nobody seems to know what an acidulated plate is. However, whatever it is, if the process is instantaneous as reported, it is very wonderful.
I do not intend to take any steps with regard to my last paper read to the R.S. <8> I think I have great cause to complain of the Council: but I have no wish to waste more time & trouble on the subject. I think the only error I committed was, in not asking a friend to explain to them the state of the case. But in general I do not think of answering an objection until it is made, & I never could have imagined that they would decide without enquiry & without any communication with the author, that the Rules of the Society had been broken, and without being sure of the fact. I believe the fact to be quite the other way. The communication was sent in first to the Royal Society. Does the Rule require that the author should keep the subject a secret till his paper is read to the Society? For instance, if I send a paper in July, may I not communicate the substance of it to the Institute before the end of November? If that is the Rule, it should be known. But I have no doubt that most of the important papers in the Transactions had been previously divulged, as to their general contents, though the details appeared for the first time in the Transactions; and indeed there have been many discoveries which it would be absurd to have kept entire secrets for many months, until the reassembling of the Society. – I do not in short believe that any rule was infringed; nor that any intelligible rules on the subject have been promulgated.
I remain Dear Sir Yours very truly
H. F. Talbot
Notes:
1. 31 Sackville Street, London residence of the Feildings, often used as a London base by WHFT.
2. Samuel Brown (1817–1856), chemist.
3. True cyanates are uncommon and rather unstable; his compound was potassium ferrocyanide.
4. Sir Humphry Davy (1778–1829), chemist.
5. Christian Friederich Schönbein (1799–1868) chemist.
6. Louis Jacques Mandé Daguerre (1787–1851), French artist, showman & inventor, as announced by Dominique François Jean Arago (1786–1853), French physicist, astronomer & man of science, ‘Nouvelles découvertes de M. Daguerre’, Comptes Rendus hebdomadaires des séances de l’ de l’Académie des Sciences, v. 12 no. 26, 28 June 1841, pp. 1228–1229.
7. Arago explained the verbal nature of the first communication, and published a 5 July 1841 letter from Daguerre to himself, in the Comptes Rendus hebdomadaires des séances de l’ de l’Académie des Sciences, v. 13 no. 1, 5 July 1841, pp. 26–27.
8. WHFT read before the Royal Society on 10 June, ‘An account of some recent improvements in Photography’. Only an abstract was published in the Proceedings of the Royal Society, v. 4 no. 48, 1841, pp. 312–315. WHFT reprinted the full text of his article in leaflets, first as The Process of Calotype Photogenic Drawing in 1841, and again in 1845 under the title The Process of Talbotype (formerly called Calotype) Photogenic Drawing.