ON THE EARLY STAGES OF INFLAMMATION 22% 
tered, the motion was commonly exceedingly slight between the pulses. Not 
unfrequently, although the arteries remained of full size, the blood moved in 
jerks, with considerable intervals of absolute stillness between the successive 
impulses which the contractions of the heart occasioned ; yet no accumulation 
of corpuscles was produced in the capillaries, however long the animal was kept 
under observation. Had any other cause of motion than the action of the 
heart operated upon the blood, there must have been a continuous flow, however 
much accelerated at each pulse ; for I must add, that there was nothing what- 
ever of recoil after each onward movement, nor anything indicating obstruction 
to the progress of the blood. 
Thus in these cases of intermitting capillary flow, it was matter of direct 
observation that the heart was the sole cause of the blood’s motion; and as 
we know that in an animal under the influence of chloroform the changes of the 
blood from arterial to venous, and vice versa, continue to occur in the systemic 
and pulmonary capillaries, and as we have every reason to believe that the 
processes of nutrition in the different parts of the body go on then as usual, 
these cases appear to prove absolutely that the forces which are concerned in 
the mutual interchanges between the tissues and the nutrient fluid do not cause 
any movement whatever. 
But even supposing that it were admitted, for the sake of argument, that 
the vital affinities do, under ordinary circumstances, cause some movement 
of the blood, but lose that power in an animal under chloroform, such an ad- 
mission would hardly affect the discussion regarding the cause of stagnation 
in inflammation ; for in a frog fully under the influence of the anaesthetic, 
in which, as we have seen, the heart is the only cause of circulation, all the 
phenomena that result from irritation of the web take place precisely in the 
same manner as in one to which the narcotic has not been administered. The 
fact that the heart, even though much enfeebled by chloroform, is capable, 
unaided by any other force, of maintaining the circulation for an indefinite 
period without the occurrence of obstruction in the capillaries, or any undue 
accumulation of corpuscles in them, affords positive proof that any other cause 
of movement which may be conceived to exist when chloroform has not been 
given, must be altogether insignificant, and that the cessation of its operation 
does not give rise to stagnation of the blood. 
1 Dr. Sharpey has for many years alluded in his lectures to the circumstance that, the weaker the 
animal, the more do the effects of the successive cardiac impulses show themselves in the capillaries 
of the webs, as evidence that the action of the heart is sufficient to account for the circulation. He 
also informs me that he has frequently verified the observation of Spallanzani, that in the gills of the 
tadpole the flow of the blood ceases completely in the intervals between the pulses produced by the 
ventricular contractions. 
