THE LIB^E OF MATTER. 405 



ehiiractoristic of li\ iii-ii' nuittor. It is for ob.scrvutioii uiul cxpcrinu'iit 

 to decide as to the deg-i;ee of smiilarity, and they have, in fact, decided 

 that the simihirity is complete. The crystals and crystalline oornis 

 studied ])y Ostwald and Taminann are the seat of phenomena (luite 

 comparaMc to those of \itaiity. 



IV. 



KVOLTTIOX AND 3*rrTAP.rLlTY OF LIVTNd MATTKIi AND lUvTTK 



MATTER. 



One of the most remarkable characteristics of a li\ine- l)einu- is its 

 evolution. It undergoes a continuous change. It starts with ii feeble 

 beginning; it is formed, grows, then in ordinary cases declines and 

 disappears, having followed a predictable course, regulated as to time, 

 a sort of ideal trajectory. 



Sii2>2>'>s((l !iii)uoh!lify i>f hratc hf>dle.'<. — It may be asked whether this 

 evolution, this directed mobility, is so exclusively a feature of tlie 

 living being as it appears, and if many brute ])odles do not present 

 something analogous to it. The response is not at all dou))tful. 



Bichat was mistaken when he cojitrasted in this respect brute l)odies 

 with living bodies. Vital properties, he said, are temporary; it is 

 their nature to exhaust themselves; in time they are used up in the 

 same l)ody. Physical properties, on the contrary, are eternal. Brute 

 bodies have neither commencement nor necessar}' end, neither age nor 

 evolution; thev remain as inunutal)k> as death of which they are the 

 image. 



JSl<>l>Uifij and rtnitahility of the sidereal uH>rld. — This is not true, in 

 the first place, of the sidereal bodies. The ancients V)elieved that the 

 sidereal world was immutable and incorruptible. The doctrine of the 

 incorrui)til)ility of the heavens prevailed up to the seventeenth cent- 

 ury. The ol)servers who at that epoch directed toward the heavens 

 the first telescope, which Galileo had just invented, were struck with 

 astonishment at discovering change in the celestial firmament that 

 they had believed incorruptil)le and by perceiving a new star that 

 appeared in the constellation of Serpentarius. Such changes no longer 

 sui'prise us. Th(> cosmogonic system of Laplace has become familiar 

 to all culti\ated minds and everyone is accustomed to the idea of the 

 mobility and <-<)ntinual e\'olution of the celestial world. ''The stars 

 have not always existed," writes M. Faye; ''"they have had a p(M-i()d 

 of formation; they will likewise have a period of decline, followed 

 by a final extinction.''' 



All th(^ bodies of inanimate nature are not, then, eternal and imnui- 

 table; th(» celestial bodies are (>minently susceptible of e\'olution, slov/ 

 indeed compared with that we observe on the surface of our globe; j)ut 

 that dispropprtion, coiresponding to the iuunensity of time and of 

 cosmic spaces as compared with our terrestrial measurements, should 

 not mislead us as to the fundanienlal analogy of the phenomena. 



