( 13i) 



CoMTE anrl BiNET and Courtier, a slight extension-movement of 

 the fingers causes a release of the cylinder. If this were the case, 

 a descending of the tracing registered in that way, would be found. 



It was natural to register also the extensor muscles of the hand 

 and the fingers. This may be very fitly done with an air-cushion. 

 In this case, the local capillary pulse is of course noted down, but 

 every local expansion of the muscles will occur as a rising in 

 the curve. 



Such a rising takes place. The influence of the spasm of the vessels, 

 which exists in the perifery, as we saw before, should be noticeable 

 here, and the tracing should descend. But on the contrary tiie tracing 

 very considerably ascends as fig. XVII and XIX show. 



The objection, that an air-cushion does not work as a volume- 

 writer, but as a sphygmomanometer, is not justified. This is also 

 to be seen on the curve traced. The deviations remain as large as 

 before in spite of the enormous rise of the curve during the sum 

 (fig. XVII and XtX). 



When an air-cushion is placed at the same time on the flexor- 

 muscles of the hand and the fingers, and is made to trace the slight 

 deviations, we see hardly a change, at the utmost an indication of 

 a slight falling of the line, which is to be regarded as a conse- 

 quence of the spasm of the vessels. 



It is tlien unvariably a volume-pulse which is noted down, and if 

 we place an air-cushion on the muscles of the calf (fig. XIX), 

 exactly the same volume-curve is obtained, as we know since Binet 

 and Courtier for the fingers, and which is represented during 

 the sum in fig. XV. There is only one explanation left: the 

 extensor muscles of hand and fingers are conti-acted to some 

 degree, or rather, for the movement does not manifest itself in 

 a change of place visible to the eye, the tonus of the extensor 

 muscles of hand and fingers has become greater. In consequence the 

 curve which has been traced during the sum by the air-cushion 

 placed over these muscles rises. 



If finally we place the air-cushion on the neck, an observation 

 like the one on the extensor muscles of the hand can be made. The 

 curve, which is here of course very much infiuenced by tlie respi- 

 ration, and which is registered by the air cushion as rising by 

 inspiration, but falling by expiration, rises during the sum. Some- 

 times the head is even visibly thrown backwards, (see fig. XX). 



Summa summarum. The tonus of the extensor nmsdes of the 

 hand and neck is augmented. 



If we take all this together, the question arises, if all these 



