Electric power. 5211 



for this purpose, were necessarily made on blood out of the 

 body, and at rest. Now, when blood is taken from the vessels, 

 it immediately undergoes a remarkable chemical change, sepa- 

 rating into a solid and a fluid part. This separation is not 

 complete for some time j but whoever takes the pains to make 

 observations on the subject, can hardly doubt that it begins to 

 take place immediately on the blood being drawn. Can expe- 

 riments on the blood, under these circumstances, lead to any 

 very satisfactory conclusions, respecting the specific heat of 

 blood circulating in the vessels of the body ? The diluting 

 the blood with large quantities of water, as proposed by Dr. 

 Crawford, does not altogether remove the objection, for this 

 only retards, it does not prevent coagulation, and some time 

 must, at any rate, elapse, while the blood is flowing and the 

 quantity is being measured, during which the separation of its 

 lolid and fluid parts will have begun to take place. 



More might be said on this subject 3 but I feel anxious to General reflee- 

 avoid, as much as possible, controversial discussion. It is my tl0ns - 

 wish not to advance opinions, but simply to state some facts, 

 which I have met with in the course of my physiological in- 

 vestigations. These facts, I am willing to hope, possess some 

 Value j and they may, perhaps, lead to the developement of other 

 facts of much greater importance. Physiology is yet in its 

 infant state. It embraces a great number and variety of phe- 

 nomena, and of these it is very difficult to obtain an accurate 

 and satisfactory knowledge ; but it is not unreasonable to ex- 

 pect, that by the successive labours of individuals, and the 

 faithful register of their observations, it may at last be enabled 

 to assume the form of a more perfect science. 



XII. 



Abstract of a Memoir upon the Origin and Generation of the 

 Electric Power, whether by means of Friction, or in the Pile 

 of Volta. By J. P. Dessaignes*. 



I HAVE the honour to offer to the class, some enquiries j . . 

 into the origin and generation of electricity by friction, 



* Read before the French Institute, Sept. 23, 1811. 



as 



