PROCEEDINGS OF THE SOCIETY. 
421 
Verhale, or official record of the awards, containing the notification of 
Marzoli’s exhibits, and of the silver medal decreed for them ; (2) they 
sent the actual Diploma, dated August 20, 1811, signed by the Italian 
Minister of the Interior, in which the exhibits and award were duly set 
forth, and the congratulations of the Minister conveyed to Marzoli 
personally. Since then he had had access to the vol. of the Commentarj 
della Accademia di Scienze, of Brescia, for the year 1808, and was thus 
able to place before the Society what he thought must be regarded as 
satisfactory evidence establishing the fact of Marzoli’s early connection 
with the application of achromatism to Microscope objectives. The 
volume he had just mentioned contained a plate drawn by Marzoli, in 
which his achromatic objectives were figured, and also the special 
apparatus he had devised for their construction. It was a point of 
interest to find that the objective received appeared to correspond 
almost exactly with the figures, and hence the probability of their 
being contemporaneous demanded no great stretch of imagination ; at 
any rate, the figures spoke for themselves, and fixed the date 1808, whilst 
the Diploma anent the award of the Silver Medal fixed the date of 1811, 
so that Santini’s claim on behalf of Marzoli’s having preceded Selligue 
in the production of achromatic objectives, was abundantly confirmed. 
The date of Selligue’s objective was fixed (1) by Charles Chevalier’s 
“ Notes Justificatives,” published in Paris in 1835, in which he stated 
that he and his father made an achromatic Microscope for Selligue in 
1823, which was exhibited at the Academie des Sciences on April 5, 
1824 ; and (2) there was Fresnel’s special report on that exhibit com- 
municated to the Academie on August 30, 1824. It would be manifestly 
unfair to Selligue to ignore the fact that his capital improvement over 
every suggestion of his predecessors was the idea of so constructing the 
achromatic doublets that they could be used in combinations of three or 
four in superposition. Marzoli’s objective was a cemented combination, 
and in the figure published in 1808, the plane side of the flint was 
downwards, as if presented to the object ; but whether this was a mere 
accident in the drawing, or whether it was intended to be used, must be 
matter of conjecture. His (Mr. Mayall’s) own conjecture was that it 
was intended to be employed as figured, for the drawing being made by 
Marzoli himself, it was hardly probable that he would have inverted the 
objective ; still it was not certain that Marzoli preceded the Chevaliers’ 
practical discovery of the improvement due to the presentation of the 
plane surface of the combination to the object to be viewed. 
There were still many obscure points in the early history of the 
achromatic Microscope which could not be satisfactorily explained 
unless access were obtained to the achromatic objectives made by 
B. Martin (1759), N. ’Fuss (1774), Van Deyl (1807), Charles (1800- 
1810), Amici (1815), Fraunhofer (1816). The late Prof. Harting had 
met with an objective by Beeldsnyder, to which he assigned the date 
1791, and, by the comdesy of Prof. Hubrecht, of the University of Utrecht, 
he TMr. Mayall) had examined it with much interest ; but the work- 
manship was not such as to give much promise for the future develop- 
ment of the achromatic system. Marzoli’s objective, just received from 
Brescia, was of excellent workmanship, and might fairly be said to have 
demonstrated the importance of achromatism in those early days. The 
