Mourne Mow GAO. American Microscopes. 277 
V.—American Microscopes and their Merits.* 
By Cuar.es SToDDER. 
Tue first of the papers given in the footnote is an elaborate attempt 
at an account of American microscopes and their merits ; but should 
have more properly been entitled an attempt to describe the micro- 
scopes made by R. B. Tolles, as of the twenty-five pages which it 
covers, twenty are given to Tolles. The second article, above named, 
but first in time, is noticed here merely to illustrate some points in 
the first, and the third, because it was preliminary to the first, which 
only elaborates more in detail what Dr. Hagen said in his verbal 
communication, and repeats statements and assertions which at the 
time they were made, Dr. Hagen was informed, by those as fully 
competent, to say the least, as himself, were erroneous; but in this 
first-named paper Dr. Hagen sees fit to entirely ignore the refuta- 
tions, and makes the same statements deliberately again, as though 
there had been no contradiction of them. There is no other course 
left for those who know him to be wrong or feel aggrieved by his 
statements, than to examine his qualifications for pronouncing 
judgment, and to show wherein he is mistaken. 
Dr. Hagen being a man of acknowledged scientific acquirements, 
and holding a reputable position at Cambridge, his opinions, given 
on a professed detail of facts, and after a claimed careful study of 
two years, published in a journal of high repute in Europe, will 
command attention and respect there, among those who have no 
opportunity to see and judge for themselves. If he had stated facts 
correctly, his paper might have been left to itself to refute his 
“opinions.” No one can object to any comparison of American 
instruments with others ; it is only asked that the comparison shall 
be made fairly, and by a competent expert. The writer proposes to 
show that Dr. Hagen’s investigation has been superficial and in- 
adequate to the task he undertook; and that he has mistaken facts 
and repeated assertions after he had been informed that they were 
erroneous. 
Dr. Hagen opens his first communication to the Boston Society 
of Natural History by saying :—“ Having worked with the micro- 
scope more than thirty years for medical and scientific purposes— 
following the gradual perfecting of the instrument—I was anxious 
to examine the power |?| of American microscopes.” 
“During the past ten years there has been great competition 
* “On the North American Microscope;” by Dr. H. Hagen, Cambridge, 
Mass,: Max Schultze’s ‘ Archiv fiir Microscopische Anatomie;’ Bonn, 2nd No., 
1870. A communication by Dr. H. Hagen on his experience in the use of the 
microscope: ‘Proceedings of the Boston Society of Natural History,’ vol. xii., p.357. 
March 10, 1869. A verbal communication on Tolles’ and Scheick’s microscopes, 
to the Boston Society of Natural History, November 10, 1869 (unpublished). 
