22 AS REGARDS PROTOPLASM, ETC. 



lowest plant or animal and those of the highest is one only of 

 - degree and not of kind. 



But, on the second head, it is not otherwise in form, or 

 external appearance and manifested structure. Not the sting 

 only, but the whole nettle, is made up of protoplasm ; and of all 

 the other vegetables the nettle is but a type. Nor are animals 

 different. The colourless blood-corpuscles in man and the 

 rest are identical with the protoplasm of the nettle ; and both 

 he and they consisted at first only of an aggregation of such. 

 Protoplasm is the common constituent the common origin. 

 At last, as at first, all that lives, and every part of all that 

 lives, are but nucleated or unnucleated, modified or unmodified, 

 protoplasm. 



But, on the third head, or with reference to unity of substance, 

 to internal composition, chemistry establishes this also. All 

 forms of protoplasm, that is, consist alike of carbon, hydrogen, 

 oxygen, and nitrogen, and behave similarly under similar 

 reagents. 



So, now, a uniform character having in this threefold manner 

 been proved for protoplasm, what is its origin, and what is its 

 fate ? Of these the latter is not far to seek. The fate of pro- 

 toplasm is death death into its chemical constituents ; and 

 this determines its origin also. Protoplasm can originate only 

 in that into which it dies, the elements the carbon, hydrogen, 

 oxygen, and nitrogen of which it was found to consist. 

 Hydrogen, with oxygen, forms water ; carbon, with oxygen, 

 carbonic acid; and hydrogen, with nitrogen, ammonia. Similarly, 

 water, carbonic acid, and ammonia form, in union, protoplasm. 

 The influence of pre-existing protoplasm only determines com- 

 bination in its case, as that of the electric spark determines 

 combination in the case of water. Protoplasm, then, is but an 

 aggregate of physical materials, exhibiting in combination 

 only as was to be expected new properties. The properties 

 of water are not more different from those of hydrogen and 

 oxygen than the properties of protoplasm are different from 

 those of water, carbonic acid, and ammonia. We have the same 

 warrant to attribute the consequences to the premises in the 

 one case as in the other. If, on the first stage of combination, 

 represented by that of water, simples could unite into something 

 so different from themselves, why, on the second stage of com- 

 bination, represented by that of protoplasm, should not compounds 

 similarly unite into something equally different from themselves ? 

 If the constituents are credited with the properties there, why 

 refuse to credit the constituents with the properties here ? To 

 the constituents of protoplasm, in truth, any new element, 

 named vitality, has no more been added, than to the constituents 

 of water any new element, named aquosity. Nor is there any 



