15 
On the Distribution of Nerves to the Skin of the Frog, 
ivith Physiological Remarks on the Ganglia connected 
rvith the Cerebro-spinal Nerve. By J. V. Ciaccio^ 
M.D., of Naples. 
(Read Nov. lUli, 1863.) 
From a paper on the Anatomy of tlie Skin of the Frog/^ 
illustrated by 28 drawings^ and which I am not able at present 
to exhibit to the public, I have extracted that portion which 
relates to the distribution of nerves_, and I hasten to lay it 
before the Society with the hope that it may meet the con- 
sideration due to so important a subject. 
On the Method of preparing the Specimens. 
I feel certain that, in most instances, the different conclu- 
sions Avhich observers have arrived at in studying the same 
object are mainly owing to the divers methods they have 
employed in preparing the objects of their investigation. No 
doubt that in every microscopical inquiry that method of 
preparation should he adopted which will distinctly show the 
organic textures in all their individual parts, and at the same 
time preserve their natural appearances from any alteration. 
But unfortunately the method possessing such indispensable 
properties is still a desideratum ; for all those usually adopted 
tend, more or less, to alter the natural appearances of the 
tissues of the body. In this inquiry, after trying the methods 
of other observers unsuccessfully, I was obliged to adopt 
again that of Dr. Beale^s, which, in a previous investigation, 
I had employed with the most satisfactory results. The spe- 
cimens from which the drawings illustrating my paper have 
been taken have all been prepared in the same way, and kept 
permanently in a compound liquid of which glycerine is the 
chief ingredient. In order to avoid falling into any error of 
observation the nuclei of the different parts composing the 
skin have been coloured by carmine, and the vessels injected 
sometimes with Prussian blue and sometimes with carmine 
solution prepared after Dr. Carter's formula. In my hands 
this new carmine-injecting fluid has answered the purpose with 
the most satisfactory results. I have very often succeeded 
with it in filling the finest capillaries so completely, that I 
have been able to determine their real size w4th the utmost 
exactness. There is, however, in carmine solutions generally 
one serious defect, which cannot at present be corrected — that 
