112 Tue Microscope. 
raphy: “We have before us a dozen photo-micrographs, by 
W. H. Walmsley, of Philadelphia; direct prints from negatives, 
apparently on bromide paper, and varying in size from 24 to 54 
inches in diameter, including diatoms, leaf hairs, transverse sec- 
tions of plants, etc. This, while one of the most difficult, is at 
the same time one of the most delightful branches of photogra- 
phy, and though we are well acquainted with the exquisite work 
of the most successful workers in England, we have seen nothing 
better, and doubt whether anything equal, to those now on our 
table. Where all are so excellent, it is difficult to discriminate, 
but a section of the stem of Helimus esculentus, one of Clematis 
Virginiarum, and a specimen of Volvox globator, are as near 
perfection as with our present optical appliances we may hope 
to come. We strongly advise those of our readers, who are in- 
terested in photo-micrographic work, to procure a few of Mr. 
Walmsley’s specimens as something worthy of being wrought 
up to.” 
—_—————~< ¢ > ___—_ 
SELECTIONS. 
THE NEW OBJECTIVES. 
For some months past it has been known that we were on 
the eve of animportant advance in objectives, depending mainly 
on the elimination of the secondary spectrum, leaving only a 
small tertiary spectrum. We alluded to the subject at the An- 
niversary Meeting, by way of supplement to the remarks of the 
President on the great| value which he had found an increase of 
aperture to be in his researches on very minute organisms with 
high powers, and we expressed the belief that the new objec- 
tives will be found to be of at least equal advantage. 
Two objectives have now been received in this country, and 
their examination has fully borne out the expectation formed 
of them, and has shown that however trifling the improvement 
might at first sight be thought to be on theoretical grounds,* it 
* Prof. Abbe writes usou this point, ** We have now made what I called in 1878 
‘the Microscope of the future,’ i. e. objectives which admit of a more perfect con- 
centration of all the rays from the object. If now (as 1 am nearly sure they will) 
microscopists should feel somewhat disappointed at being told that *‘ the Microscope 
of the future’ is nothing more and nothing betterin principle than these objectives, 
I must answer ‘It is not my fault that at this time microscopical opties is such an 
ungrateful domain of human work, that many years’ hard labour have no other 
result than a slight advance.” 
