46 
NOTES AND MEMORANDA. 
to the crowding and irregularity of shape of the pig's and human cor- 
puscles on one slide ; but this very fact is valuable, since it shows well 
the softness of those of mammalia, and their proneness to become 
misshapen by mutual pressure. Hence this photograph, duly enlarged, 
would be instructive as a diagram for lectures. Some of the others 
are admirably done, with the corpuscles more or less separate : the 
slide showing those of the dog and man is quite true to nature— as 
indeed are all the preparations ; and it is to be hoped that American 
physiologists will continue these valuable representations, which so 
well exhibit the form and comparative sizes of the blood-disks; 
especially as this subject, though full of importance and physiological 
significance, seems to be almost ignored in Europe. Dr. Eichardson, 
too, has insisted on the medico-legal value of the sizes of the cor- 
puscles, and on this point it is understood that he is still prosecuting 
his original investigations ; in connection with which there should be 
preparations of the membranous bases of the mammalian red cor- 
puscles, side by side, on the same §lide, with the entire corpuscles ; 
and then, whatever may be the exact constitution of them while circu- 
lating in the vessels of the living body, how can it be maintained, 
according to a modern view, that, out of the body, as we examine and 
wash away with water the greater part of their bulk, leaving the 
membranous bases behind, the corpuscles are mere homogeneous 
bodies, like minute drops of oil or treacle ? " 
New Microscopic Amplifiers. — The Eev. J. H. Wythe, M.D., 
exhibited two instruments of the above kind at a meeting of the San 
Francisco Microscopical Society, held on March 16. He observed : — ■ 
" From the great improvements in object-glasses, made within the 
last few years, it would be reasonable to infer that opticians have 
reached the limit of perfection in that direction, and that future 
progress in the power of the microscope must depend mainly upon the 
eye-piece, or intermediate arrangements of lenses between the eye-piece 
and object-glass. A conviction of the possibility of improvement in 
this way has led me to many experiments during the last two or three 
years, and has resulted in the discovery of the amplifiers herein 
described, by which the magnifying power of an objective and eye- 
piece may be increased fourfold or greater, without apparent loss of 
definition. In the recent edition of ' Carpenter on the Microscope ' 
(1875), the only means of amplification suggested are the employment 
of deep or strong eye-pieces, and the use of the draw-tube. The 
aplanatic searcher of Dr. Royston-Pigott (described in the ' Microsco- 
pical Journal ') is referred to as an amplifier ; but I have no experience 
in its use. The meniscus is said, by one of the journals, to have been 
used as an amplifier ; but I have seen no description of it — the article 
to which I refer omitting to state whether it is a convex or concave 
meniscus, or how it is used. The above are all the suggestions I have 
found in microscopic literature. Experimenting upon the suggestions, 
I arranged the strongly magnifying "eye-piece, which I exhibited to 
the Society upon a previous occasion, consisting of a deep convex 
meniscus, in place of the ordinary field-lens in the Huygenian eye- 
piece. This, tested upon the Flemvsigrna angulatum, &c., gave excel- 
