At a glanceKnown key applied · complete
- The letter
- A. W. van Reede, Berlin, 4 February 1792, to “Monsieur” (M. de Larrey): clear text except eleven lines of figures, 83 groups in all.
- Where
- Project catalogue item 217, from a DECODE record listed as a numerical nomenclator, partially decrypted. A contemporary hand glossed the first eight lines, but DECODE’s transcription of the gloss is garbled.
- The cipher
- William V’s “Grand Chiffre”, a one-part French code with values 1–5000, surviving as DECODE R1024.
- How it was read
- Decoded with R1024, all 62 message groups give sense at once, with one transcription correction (4204 to 4202, tro). No cryptanalysis was needed.
- What it says
- There is lemon juice (citron) on the four blank half-pages of the enclosure; M. de Larrey is to warn the Prince of Orange and hand him the letter. “Les chiffres suivants sont des non-valeurs”: the 21 groups after that are nulls.
- Still open
- The enclosure, which carried the actual news, is not on the record. The word after “pour ne pas” is uncertain.
01 The document and the key
Berlin, 4 February 1792, Van Reede to “Monsieur”, in clear except for eleven lines of figures separated by dots, signed “A. W. van Reede”. 83 groups in all. The key is the 1782 one-part French Grand Chiffre of William V (KHA A29 inv. 301, DECODE R1024, values 1–5000), the same one that decodes R1026, R1027 and the control R1028.
02 The decoded text
4519 604 886 54 3032 1131 2476 1777 3104 4202 130 4152 2012 2217 2743 2137 1896 1601 801 1496 67 4896 2664 4102 1959 4242 3192 2604 51 3608 1406 119 3430 2123 55 465 1497 488 1496 4493 315 908 2019 2222 1945 131 3194 4694 4102 1067 231 604 186 4115 3439 2659 2847 4131 2364 148 2900 64
Monsieur de Larrey est averti qu’il y a du citron sur les quatre demi-pages blanches de l’incluse. Il voudra bien en prévenir Monseigneur le Prince d’Orange et avoir la bonté de lui remettre ma lettre, que je n’adresse point pour ne pas [pas-ser?]… Les chiffres suivants sont des non-valeurs.
“M. de Larrey is warned that there is lemon juice on the four blank half-pages of the enclosure. He will kindly tell His Highness the Prince of Orange and be so good as to hand him my letter, which I do not address [to him] so as not to … The figures that follow are nulls.”
Larrey is the Prince’s secretary. Syllables are spelled out in the code’s way: ci-tro-n, pa-ge, blanc-he, l-i-n-clu-se, vou-dra, na-dre-s-se.
The tail, 3633 3160 370 1229 3645 50 3139 3650 2768 2800 3370 1681 559 57 3268 2775 1391 1268 2239 2560 57, decodes to disconnected words (je vous remercie de, Conseil d’État, la Russie, facile, Russie, reconnoître, Archiduc): political-looking bait for anyone who opened the letter, which the plaintext itself declares void.
03 Method
Decoded DECODE’s transcription (XZ, 2020) group by group with R1024 and checked every group against the image and the interlinear gloss. One misreading corrected: 4204 (trois) is 4202 (tro), as the gloss has it. No cryptanalysis was needed.
04 What remains uncertain
- “pour ne pas 186 4115”: pais-ser as the key gives it; the intended word (perhaps passer or paraître) is uncertain (M). 604 is de in the key where the sense wants ne.
- The invisible-ink enclosure itself is not on DECODE R1057; whether it survives in KHA inv. 205 is not known.
Full texts
The transcription and the decryption of every document on this page, so that the reading can be used and checked. Short files are shown here; all are in the repository.
R1057, Berlin, 4 Feb 1792, Van Reede to William V
A cover note, not a despatch: Van Reede warns the Prince's secretary Thomas Isaac de Larrey that the real letter is written in lemon juice on the four blank half-pages of the enclosure, to be handed to the Prince of Orange; the last 21 groups are declared nulls.
Transcription
4519 604 886 54 3032 1131 2476 1777 3104 4202 130 4152 2012 2217 2743 2137 1896 1601 801 1496 67 4896 2664 4102 1959 4242 3192 2604 51 3608 1406 119 3430 2123 55 465 1497 488 1496 4493 315 908 2019 2222 1945 131 3194 4694 4102 1067 231 604 186 4115 3439 2659 2847 4131 2364 148 2900 64 3633 3160 370 1229 3645 50 3139 3650 2768 2800 3370 1681 559 57 3268 2775 1391 1268 2239 2560 57
Decryption
# R1057, Van Reede to William V, Berlin 4 Feb 1792: decipherment (copied verbatim from NOTES.md, "Reading", 22 Oct 2026) Key: the 1782 "Grand Chiffre" of William V, DECODE R1024 (`../vanreede1787/decode_grand_chiffre.py`). Transcription corrected in one place: 4204 is 4202 (*tro*, which the gloss confirms). 4519 604 886 54 3032 1131 2476 1777 3104 4202 130 4152 2012 2217 2743 2137 1896 1601 801 1496 67 4896 2664 4102 1959 4242 3192 2604 51 3608 1406 119 3430 2123 55 465 1497 488 1496 4493 315 908 2019 2222 1945 131 3194 4694 4102 1067 231 604 186 4115 3439 2659 2847 4131 2364 148 2900 64 ## Reading > Monsieur de Larrey est averti qu'il y a du ci-tro-n sur les quatre demi-pages blanches > de l'in-clu-se. Il voudra bien en prévenir Monseigneur le Prince d'Orange et avoir la bonté > de lui remettre ma lettre, que je n'adresse point pour ne pas se[r?]… Les chiffres suivants > sont des non-valeurs. ## English "M. de Larrey is warned that there is lemon juice [invisible ink] on the four blank half-pages of the enclosure. He will kindly tell His Highness the Prince of Orange and be so good as to hand him my letter, which I do not address [to him directly] so as not to [draw notice]. The following figures are nulls." The rest (3633 3160 370 1229 3645 50 3139 3650 2768 2800 3370 1681 559 57 3268 2775 1391 1268 2239 2560 57) are, by the letter's own statement, nulls; decoded they give a jumble (Conseil d'Etat, la Russie, Archiduc, reconnoître) planted to occupy a reader. Larrey is Thomas Isaac de Larrey, the Prince's secretary. Open: "pour ne pas 186 4115" (pais-ser) — probably *passer*/*paraître*, wording of one group uncertain.
Reading
# R1057, Van Reede to William V, Berlin 4 Feb 1792: decipherment (copied verbatim from NOTES.md, "Reading", 22 Oct 2026) Key: the 1782 "Grand Chiffre" of William V, DECODE R1024 (`../vanreede1787/decode_grand_chiffre.py`). Transcription corrected in one place: 4204 is 4202 (*tro*, which the gloss confirms). 4519 604 886 54 3032 1131 2476 1777 3104 4202 130 4152 2012 2217 2743 2137 1896 1601 801 1496 67 4896 2664 4102 1959 4242 3192 2604 51 3608 1406 119 3430 2123 55 465 1497 488 1496 4493 315 908 2019 2222 1945 131 3194 4694 4102 1067 231 604 186 4115 3439 2659 2847 4131 2364 148 2900 64 ## Reading > Monsieur de Larrey est averti qu'il y a du ci-tro-n sur les quatre demi-pages blanches > de l'in-clu-se. Il voudra bien en prévenir Monseigneur le Prince d'Orange et avoir la bonté > de lui remettre ma lettre, que je n'adresse point pour ne pas se[r?]… Les chiffres suivants > sont des non-valeurs. ## English "M. de Larrey is warned that there is lemon juice [invisible ink] on the four blank half-pages of the enclosure. He will kindly tell His Highness the Prince of Orange and be so good as to hand him my letter, which I do not address [to him directly] so as not to [draw notice]. The following figures are nulls." The rest (3633 3160 370 1229 3645 50 3139 3650 2768 2800 3370 1681 559 57 3268 2775 1391 1268 2239 2560 57) are, by the letter's own statement, nulls; decoded they give a jumble (Conseil d'Etat, la Russie, Archiduc, reconnoître) planted to occupy a reader. Larrey is Thomas Isaac de Larrey, the Prince's secretary. Open: "pour ne pas 186 4115" (pais-ser) — probably *passer*/*paraître*, wording of one group uncertain.
Translation
<!-- English translation of the reading in texts/R1057_decryption.md (Claude Opus 5.5, 23 Oct 2026): DECODE R1057, deciphered with the 1782 Grand Chiffre (R1024). The last words "pour ne pas se[r?]…" (groups 186 4115) are uncertain and kept as [?…]. --> # R1057, Van Reede to William V, Berlin, 4 February 1792: English translation Monsieur de Larrey is warned that there is lemon juice [invisible ink] on the four blank half-pages of the enclosure. He will kindly inform His Highness the Prince of Orange and be so good as to hand him my letter, which I do not address [to him] so as not to [?…]. The following figures are nulls.
05 Sources
- Koninklijk Huisarchief, The Hague, Prins Willem V inv. 205, via DECODE R1057 (image and transcription).
- Key: DECODE R1024, Grand Chiffre of William V, 1782.
- Companion page: Van Reede from Berlin, 1787–1793.
Notes, profile and ciphertext: targets/vanreede1792/.