Of the Nerve L 147 
to pafs into fuch VeiTels. He obferved far¬ 
ther that the Veffels in the Brain of a 
Sparrow are not fmaller than in an Ox ; and 
argues from thence, that there really is no 
other Difference between the Brain of a large 
Animal and that of a fmall one, but only a 
greater or fmaller Number of Veffels $ and 
that the Globules of the Fluid palling thro* 
them are in both of the fame Size. 
Though it does not diredtly relate to Mi- 
crofcopes , I hope I may be excufed for taking 
Notice here, that in the Year 1711, Dodtor 
Alexander Stuart -f made a Difcovery, 
that the Nerves are not elaflic, contrary to 
the Opinion of all preceding Authors ; and 
proved it by the following Experiment : 
“ Laying a Piece of Twine, about four 
“ Inches in Length, parallel to the Nerve, 
“ Artery, and Vein of thelnfide of the Thigh 
tx in an human Subjedt, and tying thefe to- 
<c gether, above and below, as foon as they 
were cut out of the Body, and laid on a 
£C Board ; the Artery and Vein were feen to 
‘ £ contract equally, to the Lofs of a quarter 
<c Part of the Length they had in the Body 
before Excifion 3 but the Nerve continued 
fC of the fame Length with the Twine, as 
in the Body.” 
- * Arc. Nat. Tom. I. Part. I. p. 38. 
f >v id. Stuart’s Lectures on Mu/cular Motion, in the Yeap 
3?3 8 >P’3- 
7 CHAP. 
