By means of Mosso's plethysmographical method, Zabludowski made experiments on the vaso-motor reflexes in massage (from one arm or leg to the other arm), and in "most cases" he found a widened, in other cases (I think possibly in all) he found a narrowed, blood stream.

Zabludowski has published a few observations on the after-effects of massage on arterial blood pressure in man. After massage of one arm the pressure in the radial artery of the other arm, from being 125 mm. Hg measured by von Basch's manometer before massage, rose 10 to 12 mm. in ten to thirty minutes.

From a similar experiment described below we obtain, however, very uncertain information. Zabludowski does not say how the pressure behaved during massage, nor does he say what kind of massage was used on the other arm, and there is strong ground for believing that the latter factor is important.

The question would be more easily settled if the conclusions arrived at from the experiments on one kind of animal held good for another. This, however, is not the case; distinct differences are found in this respect between the dog and the rabbit,* and very probably between this animal and man. This reminds me of conclusions I drew from experimenting on rabbits,+ which I mention here merely in order to call attention to the forces which may come into play.

After studying work on this subject I adopted the plan of performing my own experiments in such a way as to completely separate skin stimulation from muscle stimulation, and by this procedure I attained to clearer knowledge of the complicated vaso-motor reflexes. The experiment was as follows : - From the whole length of one leg of the animal the skin was removed; pure muscle stimulation (muscle-massage) was then performed on the muscles thus uncovered. Skin stimulation (skin massage) was then performed either with different manipulations on the loose piece of skin, which was still quite alive and continuous with the rest of the skin, or by light brushing (not stimulating the muscles) on other parts, e.g., on the other hind leg. The blood pressure was registered in the ordinary way in the carotid.

The result obtained in all the many experiments (with about forty animals) was that pure mechanical stimulation of the skin, of whatever strength (beyond the minimum which has no influence on blood pressure), by light stroking, by vigorous kneading and pinching, always produced an immediate rise of blood pressure of fairly long duration, which later returned to its level before stimulation, with or without a preliminary fall below this level. With very prolonged stimulation this fall took place while the stimulation was going on.

In the same way all the experiments showed that pure mechanical stimulation of muscle, of whatever strength, above an insignificant ineffectual minimum, whether one carefully stroked the bared muscles or pinched them gently or firmly (= petrissage), produced more or less immediately a temporary lowering of pressure, lasting ten to thirty seconds, which afterwards returned to its level before stimulation, with or without a preliminary rise. If the stimulation lasted more than thirty seconds the pressure returned to normal within that time.

In a mixed muscle and skin stimulation, as in ordinary massage, the result depends on which stimulus is the stronger. In a rabbit, if I grasp the muscles through the skin and subject them to kneading without stimulating the skin otherwise than by the finger tips fixed on a definite spot, I can easily obtain the lowering of pressure associated with the beginning of muscle stimulation. If, on the contrary, I stroke the skin (= effleurage) and so give a stronger skin stimulation over a larger area, although the muscles are stimulated at the same time, the rise of pressure due to the stimulation of the skin entirely counteracts the initial lowering due to stimulation of muscle.

* See Heidenhain and Grutzner, Pflugers Arch., 1877, p. 52.

+ E. Kleen,"On the Influence of Mechanical Stimulation of Muscle and Skin on Arterial Blood Pressure in Rabbits." Paper read before the Swedish Medical Society, April 12th, 1887; published in Nord. Med. Arch., 1888, xx. B., No. 10.

Curare greatly increases the reflex irritability of the skin; in an animal poisoned by it the rise of pressure produced by a very light stimulation of the skin counteracts the lowering of pressure due to stimulation of muscle.

Chloral, on the contrary, lowers the reflex irritability of the skin; therefore with a rabbit under the influence of chloral in certain doses, one can demonstrate with great certainty the curve due to muscle stimulation, with its initial lowering of pressure, in spite of simultaneous stimulation of the skin. If the dose is.sufficiently strong, stimulation of the skin alone produces a negative result.

For my part I can express no definite opinion as to the frequency of the pulse and the factors which influence it. In experiments on rabbits with skin stimulation predominating, I saw at the commencement of stimulation sometimes acceleration, sometimes slowing of the pulse, with high pulse waves depending upon a definite vagus reflex. With pure muscle stimulation, at least in most cases (in all those I saw), a slowing took place. Both acceleration and retardation were often followed by their opposites. I cannot agree with those (Naumann, Gopadse) who say that the strength of the stimulus is here determinative, in that a strong stimulation would produce slowing; a slight stimulation, on the contrary, acceleration. In 1888 I found that a very strong painful tapotement of the right thigh in man produced a definite acceleration; the same result, though less marked, was produced by firm effleurage of this part, and in both experiments the acceleration was followed by definite slowing after the stimulation had ceased. In experiments on different people with rather gentle stimulation I have also noticed slowing at its commencement.