REVIEWS. 429 
r. Hagen does." "That effectually terapie of Dr. Hagen's rennen 
that the American objectives “did not attain so much as other 
Dr. Hagen attempts to in the opinion. now insequi re- 
ceived in England and America, that the microscope should be so con- 
structed as to receive an inclination. He says, ‘‘the statement made b 
people here that the working with high Paus instruments (they being 
turned back) is much more convenient, as keeping the neck straight pre- 
vents the rush of blood to the head, makes rather a comical impression. 
I say comical, when we consider that for tens of years back several tliou- 
sand low stand instruments have been in daily use in Europe without 
od results.” [?] Possibly no one but Dr. Hagen has ever heard 
that the use of vertical instruments caused a rush of blood to the head; 
but the ases of all microscopists here (Dr. Hagen excepted), is 
against the use of the low stand vertical nnen a and that evils and 
imperfect work do result from the use of such. To show that the ‘‘com- 
icality " of the objection is not original with American microscopists, the 
following is d from Dr. Wm. B. Carpenters work on the micro- 
Scope, — an author iere opinion is certainly kae to Dr. Bes s thirty 
m Heini n fifteen years ago. **Scearcely less important 
* ja the capability c ‘ot mes placed in either a vertical or a horizon- 
tal fire or at any a with the RETI, kema deranging the 
adjustments of its dd to y other," is certainly a 
have so long neglected the very simple means which are at present com- 
monly employed in this country of giving an inclined position to micro- 
scopes, since it is now universally acknowledged that the vertical posi- 
tion is, of all that can be adopted, the very worst." Perhaps if Carpen- 
fi 
Dr. Hagen has so little to say of American microscope makers, other 
than Tolles, that he found it impracticable to make so many mistakes in 
regard to them. If he had taken more “ pains” he could have added ma- 
sponsible. ‘J have not in fact had an opportunity to compare Spencer's 
objectives and oculars.” ‘‘In Boston, Salem, and Massachusetts gener- 
ally, there are none of Spencer's instruments to be found;" that is be- 
cause he “spared the pains" to find them. The writer had them, and 
would have guided the enquirer to others. 
f Zentmeyer he remarks: “As near as I can find out he — - 
h 
Tolles or den Another example of the superficial DADA x 
tained by Dr. Hagen; a portion of the very oculars which he saw on Mr. 
Bicknell's orco qiti and which he gives the power of as Tolles, were 
made by Zentmeyer! Had he not “spared pains" to inquire, he could 
