48 
NOTES AND MEMORANDA. 
“ The inertness of the germs in liquids deprived of air is not due to 
a mere suspension of their powers. They are hilled by being deprived 
of oxygen. For when the air which has been removed by the Sprengel 
pump is, after some time, carefully restored to the infusion, unac- 
companied by germs from without, there is no revival of life. By 
removing the air we stifle the life which the returning air is incom- 
petent to restore.” 
High-angled or Low-angled Glasses in Microscopy, which are 
best? — This would not appear to be decided yet. Professor E. Smith, 
of New York, has lately gone in for the view that with high angles 
the depth of focus is increased. The following letter is from the 
‘American Journal of Microscopy’ (May), and is by Mr. B. Hitch- 
cock. After some preliminary observations, he says : — “ In the first 
place, it is very questionable in my mind if the resolutions which the 
Professor exhibited, point to conclusions in any way opposed to those 
generally received by working microscopists. Certainly the reso- 
lutions were difficult tests for the glasses employed, and no one would 
expect to make them with low-angled glasses. Is it not admitted by 
all microscopists that the resolution of diatoms and Nobert lines 
require high-angled objectives? I believe it is Carpenter who says 
that low or moderate angles are to be preferred for almost every kind 
of work except resolution of diatoms. The mere fact that Professor 
Smith has succeeded in resolving the objects mentioned with glasses 
of high angles, does not support his view that high angles are uni- 
versally preferable, but only confirms the general testimony in this 
regard. Unfortunately the abstract in this journal gives us no inform- 
ation as to how Professor Smith has been led to form his opinions 
so contrary to those generally accepted. It seems to the writer that 
it is time for the long-fought battle between high and low angled 
glasses to stop. His own experience teaches him that for ordinary 
work, penetration is a requisite ; but he does not deny the necessity of 
high angles for certain work. There should be no disagreement in 
regard to matters which any man of experience can test for himself, 
and the universal testimony of our best authorities, i. e. of men who 
have spent their lives in microscopical work, is against Professor 
Smith. As already stated, I do not wish to criticise what Professor 
Smith has said in his paper, but I would like to ask him why he thinks 
that ‘ most of the work in histology and pathology done with the so- 
called ‘ working lenses ’ of narrow angle, would require further atten- 
tion, and with wide-angled objectives ? ’ (I quote from the report in 
the journal.) If Professor Smith really means what this passage 
intimates, viz. that the errors of interpretation are greater with low 
angles than with high, then it certainly is a novel idea, to me at any 
rate, and it is well worth the careful consideration of microscopists.” 
Microscopy at the Geneva Congress. — An international medical 
congress will be held at Geneva from September 9 to 15 next. The 
only really microscopic paper will be that on the “ Histology of 
the Ovum, and the Function of the Zoosperms in Fecundation : ” 
reporter, Dr. Fol (Geneva). 
