244 INTERSTITIAL DEATH. 



illustrated by the gradual waste of the muscles under use ; that nervous 

 Necessity of activity is also dependent on oxidation is indicated by the 

 repair. appearance of alkaline phosphates in the urine. Generally, 

 the more active the function, the shorter the life of a part ; but even the 

 hair, the teeth, the cuticle, the activity of which is very low, are no ex- 

 ceptions, for they, too, have a limit of duration, and provisions for repair 

 or renewal. Thus, as the surface of the cuticle abrades, it is restored by 

 the development of new cells below, and their gradual drying up into 

 scales ; and as regards the teeth, the second set arise, as it may be said, 

 from germs which have been left by the first, so that when the crown of 

 the deciduous tooth dies, and its fang and vascular arrangement are ab- 

 sorbed, the new tooth is ready to take its place. 



Since it is not merely superficial parts, as the hair, the teeth, or the 

 Interstitial cuticle, but also the deep-seated or interior ones, that undergo 

 death. these changes, the appropriate designation of interstitial death 

 has been introduced. The removal of the effete material is accomplish- 

 ed by the aid of the blood, which occasions partial or perfect oxidation, 

 with a corresponding liberation of heat, and then, dissolving the products 

 that have arisen, carries them away. We have heretofore discussed the 

 question how it is that this oxidizing action of the arterial blood is lim- 

 ited to the dying parts, and how those which are yet capable of taking a 

 share in organization are protected. It appears to me that we are obliged 

 Deca de end * a dmit, ^ n the niechanism of living beings, those peculiar 

 ent on aiiotrop- conditions which both simple and compound bodies may as- 

 sume, and which are known as allotropic states in chemistry. 

 The indifference to oxidation which carbon, under the form of diamond, 

 presents, contrasts strikingly with the extreme combustibility of lamp- 

 black. The ready oxidibility of phosphorus, which causes the shining 

 from which it has derived its name, is no longer recognized in that other 

 phosphorus which has been acted on by the more refrangible rays of the 

 sun. And these are qualities which elementary atoms carry with them 

 when they go into union with other bodies, as is well displayed by the 

 two distinct forms of phosphureted hydrogen gas, bodies having the 

 same composition, but the one spontaneously combustible and the other 

 not. Some reasons have also been offered for imputing to the nervous 

 system a control over these allotropic changes, and under this point of 

 view we must regard it as having, for one of its prime duties, the regu- 

 lation of decay. These conclusions receive weight from the considera- 

 tion that in plants, in the economy of which no interstitial deaths are 

 taking place, no nervous system is found. 



