REVIEWS. 491 
respected” if it is said that there are gp enough diatomists in the 
whole country to encourage each other 
agen thinks that his attempt at ‘even pronouncing a judgment on 
the Haie instruments, caused a storm of indignation against me by yas 
resident microscopists," and accounts for it by the assertion that “w 
know that most of them are members of the Boston Optical pyri 
tion." Dr. Hagen here refers to the reception of his verbal communicas 
tion to the Boston Society of Natural History in November last. Of all 
the persons then present but two were members of that association, and 
whatever indignation was manifested was at his preposterous sti Aa 
isons of cost. Dr. Hagen then asserted that the American instruments 
cost 600 per cent. more than German of equal merit, and that Lbs cas 
objectives of the most celebrated pred could be imported to advan- 
tage." In his paper in the ** Archiv” Dr. Hagen reduces the comparative 
t 
much," but repeats his comparison as to the English ** according to Frey's 
statement." Now before this paper was written the cost of importing 
English beds was read in detail to Dr. Hagen, and it was shown 
makers’ price lists that the cost was much higher than Tolles’ 
prices ie sili objectives, and yet Dr. Hagen elects to repeat his er- 
He said th 
received, an extract from which is a good comment on all that Dr. Hagen 
"ia States $350. I compared them ne at the museum." Dr. 
Barnard, President of Columbia College, New York, writes, ** Dr. Hage 
is absurdly wrong in his comparison of the performance of the American 
and foreign objectives of the same proe.” “Tt is nonsense to make 
such comparisons as these price for price. 
No less unfortunate is Dr. Hagen in his description of Tolles’ first class 
instruments; he partially describes the plan and construction of some in- 
struments viis h he had seen— omitting, however, some of the most 
nard's report of the Paris Exposition of 1867 — constructing in this way 
an instrument which has no existence. He claims to have **seen and 
tested nine of Tolles' instruments of the largest class." The writer will 
