THe Microscope. 75 
of the present day have developed into positive facts; and yet 
we must remember that one hundred years hence our own 
boasted knowledge may be severely criticised by the scientific 
world of the future, and we in our turn may have to undergo 
the same test of comparison which we now apply to this work. 
Speaking of objects for the microscope, Baker tells us: 
“ Proper Objects for the Microscope are exceeding small Bod- 
ies, exceeding small Pores, and exceeding small Motions.” 
The solutions of practical problems by means of the microscope 
were not thought of in those days, Bacteria were unknown, and 
Diatoms and Desmids, now such common objects for the micro-. 
scope, but little known. 
The character and structure of blood was not at all well 
understood. We are told: ‘*‘ Human Blood, and the Blood of 
Land Animals, is found by the Microscope to consist of round 
red Globules, floating in a transparent Water and Serum. Each 
red Globule is made up of six smaller Globules, and each of 
these again is composed of six Globules still more minute, so 
that every common red Globule is composed of at least 36 
smaller ones.” He speaks very enthusiastically of the circula- 
tion of blood, but the manner of seeing it must have been very 
unsatisfactory. A glass tube was taken, and into it was 
squeezed a frog, newt, or any other small animal, and so a view 
of the circulation in the more transparent parts was obtained. 
What would one of these earnest microscopists, who thus labo- 
riously viewed this most wonderful sight, have said, if he could 
have seen the circulation in the web of a frog’s foot, through 
one of our modern instruments! Have seen the “ frog plate,” 
and the frog, neatly tied up in a little bundle, with the toes 
stretched out with fine cords! 
The ideas concerning “ animalecules” were very misty, 
everything of small size found in water being placed under that 
head. In Baker’s plates of ‘“ animalcules” are seen Diatoms, 
Infusorians, Crustaceans, and larval forms of beetles, dragon- 
flies, etc. He describes a Mavicula under the name of “ Oat 
Animal.” He says: “ This Creature is so very small, that no 
true judgment can be made of it, unless it be looked at through 
the greatest magnifier, nor even then without considerable at- 
tention. I commonly found two or three in a drop of the sedi- 
