Talk:Johann Heinrich Schulze

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In German, he is usually called "Johann Heinrich Schulze" not Schultz. I'm not sure what's right, but he also appears as Schulze on an indepent site of the municipality of his birthplace, see http://www.boerdekreis.de/index_122.html. Klusiwurm 07:44, 3 August 2007 (UTC)

Although Schulze is the great grandfather of photography it is important to note that Niepce, although credited with capturing the first image, did not use Silver Salts to produce images; the first person generally credited with having used silver salts to capture an image is William Henry Fox Talbot. 201.145.62.226 (talk) 00:48, 12 October 2009 (UTC)


 * Correction: Niepce did use a silver salt (the chloride, coated on paper) in 1816 to make the first recorded distinct photographs of camera images, but like his predecessors he could find no way to make them light-fast. Disenchanted with silver salts, he turned his attention to other substances and used bitumen to make the first permanent (i.e., light-fast) photocopies and camera photographs in the 1820s. AVarchaeologist (talk) 21:12, 1 November 2012 (UTC)

There is very little in the article that is true and practically nothing that can be traced to a reliable source. Schulze did no experiments with silver chloride as far as I can find so far, and certainly definitely produced no photographic images RPSM (talk) 14:29, 28 January 2015 (UTC)

Here is the complete article from the Focal Encyclopaedia of Photography 1960 edition: 1298 pp.

SCHULZE, JAHANN HEINRICH 1687 - 1744. German chemist and natural philosopher,. In 1725, discovered that light, though not heat,could darken a solution of chalk moistened with silver nitrate. In this way he produced impermanent contact copies from stencils. Biography by J. M. Eder (Vienna 1907)

End of article. RPSM (talk) 18:10, 28 January 2015 (UTC)


 * With the predictable nationalistic bias that warps so much photographic history writing, Eder claims that photography is a German invention by calling Schulze's impermanent stencil exposure impressions on a bottled slurry of chalk and nitric acid with some dissolved silver in it "photographs". Most non-German sources do not. One little-known wrinkle, if I understand the German WP article about Schulze correctly (which is far from certain, given my severely limited comprehension of German), is that Eder fumbled his patriotic act somewhat by mis-dating Schulze's discovery to 1725 or 1727. The latter is the date of the publication which served as Eder's source. He was unaware that it is in fact a reprint of a report originally published eight years earlier. Of course, countless books written after Eder's above-mentioned biography and his History of Photography have now enshrined his erroneous date as received truth. AVarchaeologist (talk) 17:38, 15 February 2015 (UTC)


 * Google translate version of the German article (unedited):

Schulze had placed a glass vial with nitric acid to a subject illuminated by the sun windowsill. There was a discoloration of the sheath water. This was related to the fact that the nitric acid had already been used previously and thus had some (residual) silver nitrate. Through experiments, he tried to find the reason of discoloration. It was unclear whether this was due to the heat radiation or the light of the sun. When heated Schulze 1717 silver nitrate in an oven, he noted that this is not obscured (darkened). Thus he could not rule out heat as a trigger for the darkening. When he partially opaque abklebte (covered) a glass bottle containing silver nitrate and exposed to sunlight, discolored after some time only the uncovered areas. The covered areas remained unchanged. With these experiments, he showed clearly that silver salts are sensitive to light.

Schulze published in 1719 his findings in the Bibliotheca Novissima Oberservationum ac Recensionum under the title Scotophorus per phosphoro inventus, seu de experimentum Curiosum effectu radiorum solarium. A reprint of the same title was made in 1727 in the Acta medica physico-Leopoldina. Eder, who pointed out that discovery Schulze in 1913 in a publication, only knew the emphasis. (could mean reprint) RPSM (talk) 13:08, 20 February 2015 (UTC)


 * Heaven help the world if this is the level of quality Google's recently hyped "revolutionary" real-time translation service will be delivering. Not suitable for use at the United Nations. Carefully picking apart the sentence "Somit konnte er Wärme als Auslöser für die Verdunkelung ausschließen", it certainly appears to me that it says Schulze could rule out heat, which is in keeping with the standard account of what he discovered, not that he could not do so, Google's exactly opposite rendering.


 * Revisiting my earlier research, recounted from vague memory above, I find that the German WP biography links a source for scans of the original 1719 publication. The bound volume as a whole is dated to 1721, but it contains what is essentially a periodical, published in sections over several years; a scan of the relevant section's 1719-dated contents page can be seen here. Groping through a paper in Latin is a task for which I am even more ill-equipped than parsing through a few paragraphs of German, but I can at least confirm that Schulze is referring to experiments made two years ("biennium") previously. So there we have hard evidence that Eder was in error and Schulze's experiments were made in 1717, not 1725 or 1727 as commonly reported, including in several Wikipedia articles. I'll change and footnote the date included in this article presently and correct the other articles in due course. AVarchaeologist (talk) 08:13, 21 February 2015 (UTC)


 * I left the Google translation untouched to avoid introducing errors because of my limited knowledge of German. Google translations need proof-reading, of course. RPSM (talk) 17:54, 26 February 2015 (UTC)


 * Understood; I simply found it shocking, and damning, that Google manages to see a negative in a short German sentence which clearly does not contain one. However unreliable it is, I'm very glad it exists when I need to get the gist of something in a language like Russian—or Greek—that's completely Greek to me.


 * No need for anyone to bother translating Schulze's Latin, as it turns out, unless simply to spot-check critical details: there is a complete translation in Appendix A of Litchfield's 1903 book on Wedgwood, now added as a cit. AVarchaeologist (talk) 21:56, 26 February 2015 (UTC)