CORRESPONDENCE. 
49 
impossibility, of tracing out the more minute vessels and ducts of 
organized structures by mere dissection could be overcome. 
"Dissection, aided by maceration; microscopic investigation, 
carried as far as the simple microscope would go, and doubtfully 
assisted by the imperfect earlier forms of compound microscope ; and 
injection, by the syringe or by the mere weight of mercury, — remained 
the sole methods of anatomical research up to within the last fifty 
years. 
" The improvement of the compound microscope in the early part 
of this century (see No. 3526), by the invention of adequate methods 
of correcting spherical and chromatic aberration, and of illuminating 
objects, has enabled anatomists to extend their investigations into 
minute structure to an unhoped-for degree, and to use magnifying 
powers of 2000 to 3000 diameters with as much confidence as was 
placed in those of a fourth that amount forty years ago." 
COKEESPONDENCE. 
Hasert's Objective System.* 
To the Editor of the * Monthly Microscopical Journal.'' 
Darmstadt, May 16, 1876. 
Sir, — In No. Ixxxvi. of your esteemed Journal, which reached me 
only recently, M. Hasert, of Eisenach, has tried by his usual means to 
put (suitably to his purpose) in a questionable light my impartiality 
and love of truth, notwithstanding that I never since the appearing of 
the first volume of my book, ' The Microscope,' viz. since 1867, met 
anywhere with any objections of his to the results of my investigations 
before. 
It is far from my intention to enter into any discussion with this 
gentleman, who is well known to us German microscopists, but I 
think it due to the readers of your Journal, few of whom may be 
acquainted with my book, to state the truth of the matter. 
To this end I need only repeat the passages in question concerning 
the " Hasert's objective " occurring in my book, ' The Microscope,' 
appending a few short remarks, for which I beg you will kindly grant 
me a little corner in your esteemed Journal. 
Vol. i. p. 119, treating of the drawing of the butterfly scales, it is 
stated, "Bruno Hasert has discovered this structure in 1847, and 
more fully treated this subject since (Of&cial Eeport of the Meeting 
of the German Naturalists and Physicians in Carlsruhe, page 212)^ 
* Herr Dippel's letter has unfortunately been sent to us in the original 
German, which is most complex in its mode of expression ; however, it has been, 
considering the peculiarity of the style, successfully translated by our corre- 
spondent W. R.— Ed. ' M. M. J.' 
E 2 
