48 
NOTES AND MEMORANDA. 
specially mentioned an instrument for the taking of microscopic photo- 
graphs. The most novel of the things exhibited are Mr. Dallinger's 
improvement, in the one case in the apparatus for securing con- 
tinuous observations of organisms, and in the other his ingenious 
contrivance for securing perfectly central illumination, both of which 
have been described in this Journal. Strangely enough, the largest 
collection of instruments is made by a private gentleman, Mr. Crisp, 
F.R.M.S. This is a most typical group, and consists of many splendid 
examples of the various types of instrument in present use. Among 
the more remarkable in Mr. Crisp's series is one called Brown's 
pocket microscope. There are also microscopes exhibiting Wenham's 
improvements. Mr. Stephenson's well-known binocular and erecting 
microscope. Chevalier Eoss, Beck, and How also have instruments 
exhibited. 
It will hardly be believed that there is no catalogue for the 
museum, yet such is absolutely the case. We know not who is to 
blame for this ; but assuredly some one's back must be broad enough 
to bear it. There is a very large handbook to be purchased for a 
shilling, in which we found nothing whatever in the shape of a cata- 
logue. In it, however, we did find a couple of articles, one by Pro- 
fessor Huxley, and the other by Mr. Sorby, which are well worthy of 
perusal by our readers. Mr. Sorby gives an admirable sketch of the 
microscope as it is, and we think one paragraph is particularly worthy 
of consideration. It is that in which, after describing the mode of 
making an object-glass, and correcting for spherical aberration, he 
says : " The attainment of all these advantages is so extremely difficult 
in the case of high powers, that even the best object-glasses are little 
more than the best possible compromises between opposing qualities, 
and it becomes a question whether lenses of high power should not he 
designed and made each for a particular class of objects, since a quality 
which is of paramount importance in one case is not in another." The 
italics are ours. We think this passage particularly suggestive to the 
makers ; for there is no doubt that what the histologist requires is a 
glass of quite different qualities from that demanded by the diatom 
observer. We shall conclude these remarks by a quotation from 
Professor Huxley's observations. The Professor says : 
"It is true that the very interesting collection of ancient and 
modern microscopes in the Collection contains a compound micro- 
scope, invented and constructed about the year 1590 (No. 3513), but 
it is little more than a toy. The seventeenth century hands down to 
us the microscopes of Leuwenhoek (3512), venerable relics of the epoch 
at which the foundations of minute anatomy were laid ; while that of 
Lyonet (8525) reminds us that the eighteenth century saw the pro- 
duction of one of the most perfect pieces of minute dissection yet 
extant — the ' Traite anatomique de la Chenille qui ronge le Bois de 
Saule.' 
"In the hands of Malpighi, Leuwenhoek, Grew, Swammerdam, 
Lyonet, Hewson, and others, the simple microscope, either as a single 
lens, or in the doublet or triplet form, did wonders ; while Ruysch's 
exquisite methods of injection showed how the difficulty, not to say 
