758 
the brain, when exposed, are exclusively 
communicated to it by the pulsations of 
the arteries situated at its basis. 
The eighth chapter is occupied with 
an account of muscular motion; and we 
here meet. with some ingenious remarks 
on the preponderance of the flexor over 
he .extensor muscles. ‘The merit of this 
theory is claimed by M. Richerand, and 
he is certainly entitled to some praise for 
his ingenuity. 
© The flexor musctes, therefore, have 
longer and more numerous fibres than the 
extensors; their insertion into bones is far- 
ther from the centre of their motions, under 
an angle more opts and which increases in 
proportion as the limbs are in a state of 
flexion: it is to these causes united that the 
flexors are indebted for the superiority they 
possess ; and the disposition of articular sur- 
faces, which are mostly inclined towards the 
side of flexure, is to be attributed to the 
Great extent of motion effected by these 
muscles. 
«« This preponderance of the flexer mus- 
eles varies according to the. periods of age. 
In. the foetus all parts are reflected on them- 
selves without proportion. This convolution 
of the new individual on itself may be per- 
ceived from the time of early gestation, when 
it resembles a French bean, suspended by 
the umbilical chord in the midst of the liquor 
_ of the amnion; the embryo floats in a ca- 
Vity, where it becomes progressively more 
confined as it advances towards the time of 
birth. This extraordinary flexion of parts, 
necessary for the product of conception, ac- 
commodates itself to the elliptical form of 
the uterus, and concurs to afford the muscles 
that effect it, the superiority which they main- 
tain during the remainder of life. 
«© The new-born infant preserves in a re- 
markable manner the habits of gestation, but 
as it advances in growth it becomes less 
éurved: frequent pandiculations or stretch- 
ings denote the endeavour to establish a just 
ropertion between the muscular powers. 
When the infant is able to stand erect, and 
left to 11sclf, all its parts are in a state of se- 
mi-flexion, its walk tottering, continually 
pressing towards the*point of support. But 
in middle life the preponderance of the flex- 
ors over the extensors beeome less apparent ; 
man possesses the full and entire exercise of 
his loco-imotive faculties, but as he advances 
MEDICINE, SURGERY, ANATOMY, &c. 
in age this vigour abandons him ; the exter 
sor muscles gradually return to that state of 
relative debility, in which they were during) 
infancy, and become incapable of completing, 
the action of standing in a firm and durable 
manner. 
«« The state of our limbs during sleep re- 
sembles that of the foetus, which, according 
to Baffon’s remarks, may be considered in a 
sound sleep: its cessation in man, as well as 
the generality of animals, is followed by fre- 
quent pandiculations. We stretch the fimbs 
io restore to the extensors a degree of tone 
necessary for the functions that they are to 
perform when awake. Barthez refers the 
erowing and fluttering of wings, by which 
the cock announces his waking, to a similar 
purpose,” 
The three remaining chapters are on 
the voice and speech, on generation, on, 
ages, temperaments, the varieties of the, 
human species, &c. and these, with some 
observations on old age, the probabili. 
ties of human life, on death, and putre- 
faction, conclude the volume. 
in composing these elements of phy-, 
siology, M. Richerand has made ample 
suse of the labours of others, and has 
added very little of hisown, Except in 
two instances, we have not found an 
original observation relative to the ani- 
mal economy: the author seldom rises 
above the quotation of a surgical case, 
and these are not much to the point. 
Anelementary work ought to contain 
the principal and most striking facts ar- 
ranged in a proper manner, and detailed 
jn plain and simple language. In these 
respects the present work is very defici- 
ent; it may be found useful, however, 
to those who are desirous of becomin 
acquainted with some of the genera 
doctrines of physiology, and it may 
serve as a work of reference to those. ° 
who may want to refresh their memory, 
with the rudiments of this science. We. 
cannot say how faithful the translation 
may be, as we have not had an oppor- 
tunity of comparing it with the original. 
Very little can be said in praise of its 
elegance and perspicuity. Many words: 
occur like the following: musgulosity, 
quiesce, cherubims, p. 29, &C. 
Arr. XXXI. A Course of Medical Studies: containing a comparative View of the, 
anatomical Sirudture of Man, and of Animals; a History of Diseases; and an Actount 
of the Knowledge hitherto acquired with regard to the regular Action of the different 
Organs. 
A Work chiefly designed for the Use of medical Students. By J. Burnin, 
M.D. Translated from the French. 3 vols. 8vo. 
THE object of this work is to convey 
populzrinstruction on the physical nature 
of man, by giving a comparative view 0° 
the anatomical structure of animal bo, 
