220 On vniscular Motion. 



is a certain criterion of" death. The reiterated Visitations of 

 blood are not essential to muscular irritability, because the 

 limbs of animals, separated from the body, continue for a 

 long time afterwards capable of contractions and relaxa- 

 tions. 



The constitijept elementary materials of which the pecu' 

 liar animal and vegetable substances consist, are not sepa- 

 rable by any chemical processes hitherto instituted, in such 

 manner as to allow of a recombination uito their fjrmer 

 state. The composition of these substances appears to be 

 naturally of transient duration, and the attractions of the 

 elementary materials uhich form the gross substances are 

 so loose and unsettled, that they are all decom.posed without 

 the intervention of any agent, merely by the operation oi 

 their own elementary parts on each other. 



An extensive discussion of the chemical properties at- 

 taching to the matter of nniscle would be a labour unsuited 

 to this occasion : I should not, however, discharge my pre- 

 sent duty, if I omitted to say that all such investigations 

 can only be profitable when etl^ccted by simple processes, 

 and when made upon the raw materials of the animal fabric, 

 such, perhaps, as the albumen of eggs, and the blood. But 

 until, bv synthetical experiments, the peculiar substances 

 of animals are composed from what are considered to be 

 elementary materials, or the changes of organic secretion 

 imitated bv art, it cannot be hoped that any determinate 

 knowledge should be established upon which the physiology 

 of muscles may be explained. Such researches and inves- 

 tigations promise, however, the most probable ultimate suc- 

 cess ; since the phaenomeua are nearest allied to those of 

 chemistry, and since all other hypotheses have, in theif 

 turns, proved unsatisfactory. 



Fads and ExperimenH tevding to support and illustrate the 

 preceding Argunie/it. 

 An emaciated horse was killed by dividing the medulla 

 spmalis, and the large blood-vessels under the first bone of 

 the sternum. 



The temperature of the flowing blood was 103° 

 Spleen - 103 



Stomach - 101 

 Colon - 98 



Bladder of urine 97 

 Atmosphere - 30 

 Three pigs, killed by a blow on the head, and by th6 

 inmiediate divisioii of the large arteries and veins, entering 



the 



