4810.] 
mediately removes the giddiness; and 
then by rising a second time more gra- 
dually, the same sensation is avoided.” 
In his observations on the salutary ef- 
fects of riding, &c. Dr. Wollaston os 
serves, that although the term gestuti 
is employed by medical writers as a ge- 
neral sterin comprehending aiding oa 
horseback, or in a carriage, yet he sus- 
pects that no explanation has yet been 
given of the peculiar advantages of exter- 
nal motion, nor does he think that the 
benefits to be derived ‘from carriage-ex- 
ercise have been estimated so highly as 
they ought. Under the term exercise, 
active exercise has too frequently been 
confounded with passive gestation, and 
fatiguing efforts have been substituted 
for motions that are agreeable, and even 
invigorating, when duly adapted to the 
strength of the invalid, and the nature of 
his indisposition. His explanation of the 
effects of external motion upon the circu- 
lation of the blood is founded upon a 
part of the structere ebservable in ‘the 
venous system. The valves allow a 
free passage to the blood, when pro- 
pelled forward by any motion that as- 
sists its progress; bat they oppose an 
immediate obstacle to such as have a 
contrary tendency. The circulation. is 
consequently helped forward by every 
degree of gentle agitation. The heart is 
sup ported in any laborious effort; it is 
assisted in the great work of restoring a 
system, which has recently struggled 
with some violent attack ; or-it Baio 
ed as it. were to rest -from a labour to 
which it is unequal, when the powers of 
life are nearly exhausted by any lingering 
disorder, In the relief thus affurded to 
an organ so essential to life, all other 
vital functiéns .must necessarily particl- 
pate, and the offices of secretion and as- 
similation will be promoted during such 
comparative repose from laborious exer- 
tion. Eventhe powers of the mind are, in 
many persons, manifestly atfected by these 
kinds of motion. [tis not only in cases 
of absolute deficiency of power to carry 
ov the customary circulation, that the 
beneficial effects of gestation are felt, 
hat equally so, when comparative inabi- 
lity arises from redundancy of matter to 
he propelled. When, from fuliness of 
blood the circulation is obstructed, the 
“whole system Jabours under a jeeling of 
agitation, with that sensibility to sudden 
impressions which is usually termed ner- — 
vousness. The mind becomes Reale 
of any deliberate consideration, and i 
- ympressed- with horrers that have no 
Royal Society of London. ; 259 
foundation but in a distempered imagi- 
nation. The composed serenity of mind 
that succeeds to the previous alarm, is 
described by some persons wish a degree 
of satisfaction that evinces the decided 
influence of the remedy. Dr. Wollaston 
quotes a very striking fact in justification 
of his theory ; and adds, “Tf vigour can 
In any instance be duecedye given, a man 
may certainly be said to receive it in the 
most direct mode, when the, service of 
impelling forward the circulation of his 
blood is performed by external means. 
The first mover of the systems is therebs 
wound up, and the several subordinate 
operations of the machine must each be 
performed with greater freedom, in cons 
sequence of this general supp sly of power.” 
In many cases (he further observes), the 
cure of a ieee has been solely-owing 
to the external agitation of his body, 
which must bé allowed to bave had the 
effect of reheving the heart and arteries 
from a great part of their exertion in 
propelling the blood, and may therefore 
have contributed to the cure ‘by that 
means only. Different devrees of exer= 
cise must be adapted to the ditterent de- 
grees of bodily strength; and in some 
cases, a gentle, long-continued, and per- 
Taps incessant, motion inay be requisite :. 
and, in these circumstances, sea voyages 
have sometimes been attended with re= 
markable advantage. ‘ 
ft will be reco lected by our readers, 
that a young man in the autumn of last 
year, weat into a room in which were two 
healthy raitie snakes, and that after 
teasing the mi some time, one of them bit 
him, of whic +h wound he lingered from 
the 17th of October ull Nover nber 4th, 
whenle-died. Mr, Everarn Hour, who 
attended the man through his sufferings, 
has laid before the Royal Society a-most 
accurate and minute statement of the 
symptoms that occurred, and of the 
means made use of to avert the evil. 
After this, he refers to several other cases: 
sent from India to Dr, Patrick Russell, 
and to an experiment which be made in 
the year 1782, while on the island of St- 
Lucia: from all wich he infers, that the 
effects of the bite ofa snake vary accord- 
ing to the intensity of the poison - When 
it 1S very active, the docal irsttatian is SO 
sudden aud.so violent, that death soon 
takes place, but the only alteration of 
structure of the body is in the parts close 
to the bite, where the cellular membrane 
is completely destroyed, and the neigh- 
bouring «muscles very. considerably 10= 
flamed, When the poison is less intense, 
the 
a 
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