deinde dexter, ultimo auricula dextra. Ita a quo
incipit vitalis facultas et pulsus primo, deficit
ultimo.” 1
Harvey contends that the heart is the sole
mover of the blood. He observes :—“ Ad distri-
butionem et motum sanguinis, impetu et violentia
opus est, et impulsore, quale cor est; turn quia
sanguis sponte sua (quasi versus principium, vel
pars ad totum, vel gutta aquae sparsae super tabu-
lam ad massam) facile concentratur et coit (uti a
levibus causis solet celerrime; frigore, timore,
horrore, et hujusmodi causis aliis), turn, ultra,
quia e venis capillaribus in parvas ramificationes, et
inde in majores exprimitur motu memhrorum et
musculorum compressione, [et eo] proclivis est
magis et pronus sanguis ut e circumferentia
moveatur in centrum, quam e contrario (quamquam
valvulae impedimento nullae forent) ; unde ut
principium relinquat, et loca stricta et frigidiora
ineat, et contra spontaneum moveatur, turn violentia
opus habet sanguis, turn impulsore: quale
cor solum est, et eo quo dictum est modo.”2
1 Vide Gulielmi Harveii Opera Omnia, a Collegio Medicorum
Londinensi édita : MDCCLXVI; Exercitatio altera ad Riolanum ;
Pp. 132—136. 2 Ibid. p. 72.
Harvey denies all pulsific power in the arteries.
By this term, however, he does not mean a power
of contraction, hut of dilatation ; and he argues
very strongly against any such supposed power in
these vessels : — | Arterias distendi quia replentur,
ut sacculi et utres, atque non repleri quia disten-
duntur, ut folles, facile et aperte demonstrare
me posse, et palam antehac demonstrasse,
existimo.” 1
The muscular contractile power or irritability
of the arteries does not appear to have been suspected
by Harvey, or to have occupied the minds
of the physiologists of his time.
But Haller and Spallanzani deny all contractile
power in the arteries, after the most attentive
consideration given to the subject. The former
observes:—“ Les artères sont entièrement destituées
de toute force contractive, et le sang se meut
à travers les vaisseaux de cette classe, comme si
c’étoit autant de tuyaux de verre.” “ Les veines
sont, comme les artères, sans dilatation et sans
constriction.”2 The motion of the blood observed
1 Ibid. p. 13.
2 Deux Mémoires sur le Mouvement du Sang ; par M. Alb. de
Haller. Lausanne : pp. 236 ; 263.