48 Observations on Dr. Carus’s Discovery 
the two philosophers ; who had either invited no guest to their 
banquet, or found none who relished in prospect the piéce de 
résistance. A huge dish of snails was placed before them: 
but philosophers are but men, after all; and the stomachs of 
both the doctors began to revolt against the proposed experi- 
ment. Nevertheless, if they looked with disgust on the snails, 
they retained their awe for each other: so ffiat each, conceiv- 
ing the symptoms of internal revolt peculiar to himself, began, 
vite infinite exertion, to swallow, in very small quantities, 
the mess which he internally loathed. Dr. Black, at length, 
* showed the white feather,’ but in a very delicate manner, as 
if to sound the opinion of his messmate. ‘ Doctor,’ he said, 
in his precise and quiet manner, ‘ Doctor, — do you not think 
that they taste a little —a very little, green t 2? *¢ D—d green, 
> A 
d—d green, indeed, — tak’ them awa’, tak’ them awa’,’ voci- 
ferated Dr. Britian, starting up from table, and giving full 
vent to his feelings of abhorrence. And so ended all hopes of 
introducing snails into the modern cuisine: and thus philoso- 
phy can no more cure a nausea than honour can set a broken 
limb.” (Quart. Review, xxxvi. 197.) 
I am, Sir, &c. Gad: 
Arr. XI. Observations relative to Dr. Carus’s Discovery of the 
Circulation of the Blood in Insects. By Wi1LL1aM SPENcz, Esq. 
F.L.8. 
Sir, 
One of the obscurest points of the physiology of insects 
has always been that of the circulation of their blood. The 
most superficial observer of many of the large thin-skinned 
larvee could scarcely fail to observe the evident regular pulsa- 
tion of a fluid in a vessel running along the back and it was 
naturally considered that this fluid is analogous to the blood 
of larger animals: but as even the microscopic observations 
of Se yaninierdan and Lyonet had never detected any thing 
like blood-vessels in other parts of the body of insects, a circu- 
lating system has been generally denied to this class, which in 
this circumstance has been thought to differ from some of the 
classes immediately connected with it. It was reserved for 
that eminent physiologist, Dr. Carus of Dresden, physician to 
the King of Saxony, to remove this obscurity by the interesting 
and important discovery which he made and published a few 
years ago (and the substance of which is given in an appendix 
to Mr. Gore’s translation of his Lntroduction to the Comparative 
