From left to right:
'Microscope achromatique réduit' by Trécourt and Oberhaeuser.
Signed on the tube:

Large drum microscope by Achille Trécourt & Georges Oberhaeuser in its case.

From left to right:
One of the last petrographic microscopes manufactured by Nachet, sold in November 1922.
Signed on the base:

Large Nachet microscope with fusee chain-driven focusing control.
The focusing mechanism is not by the usual rack and pinion, but by chain winding round a spindle controlled by the knurled wheels. This gives a smooth motion without backlash.
Inclination angle is retained by fusee chain.
Signed on the base:

Large perfected model microscope by Nachet in its case.

Three dissecting microscopes by Nachet.
In the foreground: two prototypes.
The stand on the left is most likely designed by Henri de Lacaze-Duthiers and is a modification of the dissecting microscope proposed by Charles Robin.
The signature on the arm reads:

Carl Kellner style microscope manufactured by Ludwig Engelbert and Moritz Hensoldt.
The microscope is signed on the limb:

Silbermann-type heliostat
Signed on the drum:

Draft of letter from Camille Nachet to the French Academy of Sciences.
This letter is reproduced in the proceedings of the French Academy of Sciences, session held on monday 31st May 1847 (Comptes rendus, t. XXIV, pp. 976-77).

Notes written by Alfred Nachet concerning his father Camille.
These notes were included in the book 'Collection Nachet' published in 1929 by Albert Nachet, Alfred's son, pages 124-125.

History of the Nachet company written by Albert Nachet in ink, corrections in pencil by Alfred Nachet.
These notes were reproduced in the catalogue of the 'Industrie française des instruments de précision' (1901-1902, p. 172), unfortunately without corrections.

Patent application by Georges Oberhaeuser (Georg Oberhäuser) and Achille Trécourt for a "microscope achromatique vertical à miroir fixe avec platine à tourbillon...".
Dated 17th August 1837.

Cross-section of microscope appearing in the drawings belonging to the descriptive report.
The collection holds an example of this microscope.

Final patent for a 5-year term, dated 13th October 1837.

Exhibitor's pass issued to Adam Prazmowski, agent for Edmund Hartnack, for the 1867 Universal Exposition in Paris.

Draft of Adam Prazmowski's application for naturalization.

Letter from Adam Prazmowski to Mr. Nachet concerning the sale of his company, dated 7th October 1883.

Deed of sale; Bézu, Hausser and Company (successors to Prazmowski) to Alfred Nachet, 9th July 1896.

Invoice for Mr. Nachet.
The selling price was 25000 francs.

Alfred Nachet's receipt for purchase of the firm Bézu, Hausser and Co. and involved expenses.
Dated 3rd December 1897.

Letter from Frédéric Villot (keeper of the paintings in the Louvre Museum) in which he acquainted Henri van Heurck with the Nachet condenser, dated 27th June 1865. Van Heurck explicitly refers to this letter on page 78 of his 1891 book 'Le Microscope' (page 80 in 1893 English edition).

Exact plan of the arrangement of the lenses and of their curvatures of the Nachet condenser. These drawings belonged to the letter of Frédéric Villot, dated 27th June 1865.

Another letter from Frédéric Villot to Henri van Heurck, dated 12th June 1865.

A non-exhaustive list of makers of interest:

• Nachet, rue de la Monnaie, Paris
• Nachet, Opticien, Rue Bouchez 1, Paris
• Nachet, Opticien, Quai aux Fleurs 17, Paris
• Nachet, Opticien, Rue des Grands Augustins 1, Paris.
• Nachet, Opticien à Paris, Rue Serpente, 16
• Nachet et Fils, rue Serpente, 16. Paris.
• Nachet et Fils, 17, rue St. Séverin, Paris.
• Nachet, 17, rue St. Séverin, Paris
• Nachet à Paris

• Bouquet et Georges Oberhaeuser à Paris
• Trécourt [Trecourt] et Georges Oberhaeuser, Place Dauphine N°19, Paris
• Georges Oberhaeuser [Oberhauser], Place Dauphine 19, Paris

• Amici, Modena
• Amici, Firenze
• Filippo Pacini, Pistoia
• Angelo Poggiali, Firenze