i879J 
Notes . 
823 
Microscopy. 
Dr. Pelletan, in the “Journal de Micrographie,” 3me annee 
(No. 3, p. 139), complains of the little scientific value of the 
majority of microscopic objects prepared for sale. Prepara- 
tions of diatoms are the most satisfactory as they are the 
easiest to make, and J. D. Moller’s “ Typenplatte ” is espe- 
cially commended by Dr. Pelletan; certain vegetable prepara- 
tions, sections of dense substances, animal, vegetable, and 
mineral, are noticed as being very instructive. But the his- 
tological preparations, whether of man or other vertebrates, 
or of the invertebrates, are stated to be precisely those of 
least value. The usual inseCt preparations meet with but 
little favour from the writer ; they present, he says, a mag- 
nificent appearance, but the integument is all that has 
been preserved, and the little that remains of the internal 
organs is represented by a uniform transparent mass, in 
which the microscopist finds nothing to study. Some of 
the English preparations mounted without pressure are very 
successful, particularly those of spiders, some of which 
show the internal organs very fairly. Complaint is made that 
the preparers of animal anatomical subjects have not sufficient 
knowledge to understand what it is necessary to make visible, 
and what is the characteristic detail to be rendered evident, in 
order to make the preparation instructive. They imagine it to 
be sufficient to take a piece of tissue, injeCted, or otherwise, 
harden it, make longitudinal and transverse sections, then steep 
it in some dye, mount it in a beautiful cell, and by these means 
obtain a slide useful for something. For example, in certain 
“ commercial ” histological preparations the writer notices dis- 
associated muscular fibre, a torn nerve filament, a slice of con- 
junctive tissue, and the nerve terminations on a muscular fibre. 
What is learned ? The muscular fibres have not been stretched, 
the sarcolemma is not evident, nor the nodes, nor the least 
detail of the striae, discs, and transparent spaces ; as to the other 
portions all is confusion, and nothing clearly displayed. The 
complaint is certainly true, but, it is to be feared, little will be 
done, as well made animal preparations are costly, and the pur- 
chasers few. Pretty objects are those which pay best. 
Dr. John Matthews, F.R.M.S., Vice-President of the Quekett 
Club, has contrived a machine for making sections of such sub- 
stances as bone, hard wood, ivory, nut, and other materials 
which are too hard to be cut with the seCtion knife, and not of 
a nature to require the lapidary’s wheel. The carriage holding 
the saw runs smoothly yet firmly between friction rollers, arid 
derives its reciprocating motion from a crank, which can be 
turned either by hand, or when a higher speed is required, 
driven by a treadle and pulley. The saw is provided with 
