404 Scientific Intelligence. [May, 
train. Both balls appeared to have had great force. The ball from 
the muzzle went clear through a sort of flag slate, about three 
quarters of an inch thick, which was placed before it. The ball 
from the breech struck the ground, which it ploughed up, and then 
hit a large stone, which altered its shape. The first ball, after 
passing through the flag slate, was found at the bottom of a wall, 
which it had also struck, and which had flattened it nearly into the 
form of a penny piece. 
Probably the great tenacity of the iron of which gun-barrels are 
made is the only thing of practical use to be deduced from these 
experiments. Jam persuaded, however, that many of your readers 
will think them curious: and if you should think fit to give them a 
place in the Annals, the accompanying sketch will give a clearer 
idea of the form of the barrel than any description. It is to be 
observed, however, that the curve is not all in the same plane; for 
when laid on a surface, it only touches from A to D; the remaining 
portion rises gradually in a kind of spiral curve, until the muzzle, 
C, is about five inches clear of the surface ; so that the ball had its 
direction twice altered before getting out. 
Ft. » 
Length of the barrel straight ....5....0400c.00s seseessoe coaches Oo \A 
Henptor helmed BGS Ast ke. ts oct ecs cies oome « wag doles ceteae ig! 
Length of the line BD........ baila Stelsars SPE ME oeib ice teieepiale 0 10% 
lremain, dear Sir, yours most truly, 
J. MENZIEs. 
IX. On the Introduction of Vaccine Matter into America. 
(To Dr. Thomson.) 
SIR, 
In the last number of your Annals a correspondent under the 
signature of G. expresses his surprise to find it stated in my Me- 
moirs of the Life and Writings of the late Dr. Lettsom, that the 
vaccine lymph was first sent across the Atlantic by Dr. L., and con- 
signed to the care of his friend Dr. Waterhouse, of Cambridge, 
Massachusetts, from whence it spread through the United States. 
This is said to be untrue; that “ vaccine lymph had been previously 
sent by Dr. George Pearson to Dr. Chichester, now a resident phy- 
sician at Bath, but at that time in very extensive practice at Charles- 
