The copperplate was not part of any of the early collections and is almost certainly not in existence anymore.

Tholinx was the brother-in-law of Jan Six, who in turn was married to a daughter of Nicolaas Tulp, the fysician for whom Rembrandt painted his first Anatomic Lesson in 1632 (A51, Bredius 403, Mauritshuis). Tholinx was Inspector of the Collegium Medicum. He was succeeded by Johan Deyman, for whom Rembrandt painted his second Anatomic Lesson in 1656 (Bredius 414, Rijksmuseum). As he did in several of his paintings, Rembrandt uses the light reflecting from the book in front of Tholinx to illuminate his face.
In the 1st state this reflection is overdone, it is corrected in the 2nd state.

Rembrandt made a painting of Tholinx in the same year (Bredius 281, 1656, Musée Jacquemart-André in Paris).

NH lists no less than eight copies, showing the popularity of the plate. Four copies are in the same direction. Copy B is by Pierre François Basan (118 x 152 mm, two states, WB 1). Copies D, E and G are anonymous.
There are four copies in reverse. Copy A is signed Rembrandt f.  published by Hertel (145 x 147 mm, WB 6). Copy C is by Francesco Novelli. It is in the collection ‘Rembrandt in Black & White’, number 341 (his nr 8, 202 x 166 mm, WB 3). Copy F is signed by John Burnet (195 x 147 mm, WB 5). Copy H is signed Rembrandt f. (140 x 146 mm, WB 4).

The etching is considered as special by Bartsch, Coppier, Rovinsky, De Claussin and Wilson.

NH, as Nowell-Usticke, lists two states, most other authors three. The difference in states based on the shape of the beard is not followed by NH and NU.
In the 1st state (NH) the upper part of the sitter’s breast is shaded on the right side with cross-hatching only.
In the 1st state (WB, R771) the beard is forked, whereas in the 2nd state (WB, R772) it is square.
In the 2nd state (NHD, NU/3rd state WB, R773) there is strong horizontal shading on the breast.

Only four impression of the 1st and nine of the 2nd state are known.
Of the 2nd state there is one impression on Japanese paper and a counterproof. Both in the British Museum.

In the 1st state: Strasbourg lily, E.c and E.zz (c. 1656);
In the 2nd state: Foolscap with five-pointed collar, G.b (c. 1656);

H 289, BB 56-2, G 264, M 170, Mz 73, RA 771-773, Cl 281, W 286, Bl 188, Du 270, CD 246, S 130.
Late Rembrandt p. 177;