164 THE MICROSCOPE. [August, 



be practically certain, this instrument takes rank as the earliest 

 comi:)ound microscope yet known ; it carries the invention back 

 from the 17th to the i6th century, from Italy to the Netherlands, 

 from Galileo (already rich in honors) to Janssen, and it vindi- 

 cates our exposition as a tricentenial. 



A cut of Janssen's MicroscoiDe may be seen in the '• Cantor 

 Lectures on the Microscope," p. 7. 



The remainder of the historical exhibit presented an interesting 

 variety of the curious and often fantastic constructions of the 17th,* 

 iSth and earlvpart of the 19th century. Their optical parts were 

 so primitive and inefficient as to impress one, at the present day, 

 with great respect for the intelligence and perseverance of any- 

 body who succeeded in doing any useful work with them. Their 

 stands were clumsy and often grotesque, many having w^ooden 

 bases and huge bodies of wood or pasteboard covered with paper 

 or leather, and often highly decorated with chasing or paint or 

 gilt, the wdiole appearance being suggestive of the cabinet-mak- 

 er's and bookbinder's rather than of the optician's art ; and the 

 brass-work, wdiat there was of it. followed the fashion of the cen- 

 turies, running into scrolls and dolphin or dragon forms and in- 

 genious elaborate devices instead of the severe practical utility of 

 the present day. Many of the instruments were focused by screw- 

 ing the whole body down with a very coarse movement, through 

 the collar wdiich supported it, toward the stage ; a method re- 

 vived in fine brass-work in the clinical microscope of Tolles a few 

 years ago. The chief individual exhibitors in this department 

 were Dr. Van Heurck. of Antwerp, and A. Nachet, of Paris, 

 both of whose collections were large and attractive. 



Among the instruments most interesting for personal reasons 

 were three genuine microscopes of Leeuwenhoek (1673), which 

 had been used in his studies by that pioneer in histology, and 

 were exhibited here by an artist jDainter (P. A. Haaxman), of 

 Delft, a lineal descendant of Leeuwenhoek's sister ; also an au- 

 thentic simple microscope of P. Lyonnet, accompanied with the 

 dissecting instruments he used with it in his famous study of cat- 

 erpillars, and by the numerous plates engraved by his own hand 

 (Maastricht, 1760), contributed by the Royal Zoological Society 

 of Amsterdam ; a fine compound microscope presented to Buftbn 

 by his pupils (inscribed '' « 7iot7'e maitre par ses cleves^') in 

 1758, having a wooden base with three knobs to give a tripod 

 effect, with a stout body, some 3 inches wide and 7 long, sup- 

 ported vertically by heavy brass-work and supplied with coarse 

 and fine adjustments; and a microscope by Amici, that formerly 

 belonged to the botanist Schleiden (1S37). 



Of objectives aside from the regular outfit of the various mi- 

 croscopes, there were globules from melted glass of 1750 and 1815 ; 

 lenses of garnet and of sapphire, by Charles Chevalier (1S25) : 



