420 ON CONCRETIONS, SPICULES, ETC. [ch. 



fact, or the great probability, that "the tenacity with which 

 Pasteur fought against the doctrine of spontaneous generation was 

 not unconnected with his behef that chemical compounds of one- 

 sided symmetry could not arise save under the influence of life*." 

 But the question whether spontaneous generation be a fact or not 

 does not depend upon theoretical considerations : our negative 

 response is based, and is so far soundly based, on repeated failures 

 to demonstrate its occurrence. Many a great law of physical 

 science, not excepting gravitation itself, has no higher claim on 

 our acceptance. 



Let us return then, after this digression, to the general subject 

 of the forms assumed by certain chemical bodies when deposited 

 or precipitated \N^thin the organism, and to the question of how 

 far these forms may be artificially imitated or theoretically 

 explained. 



Mr George Rainey, of St Bartholomew's Hospital (to whom 

 we have already referred), and Professor P. Harting, of Utrecht, 

 were the first to deal A\ith this specific problem. Mr Rainey 

 pubHshed, between 1857 and 1861, a series of valuable and 

 thoughtful papers to shew that shell and bone and certain other 

 organic structures were formed "by a process of molecular 

 coalescence, demonstrable in certain artificially-formed products f." 

 Professor Harting, after thirty years of experimental work, 

 pubHshed in 1872 a paper, which has become classical, entitled 

 Recherches de MorpJwlogie Synthetique, sur la prodtiction artificielle 

 de quelqties formations calcaires brganiques ; his aim was to pave 

 the way for a "morphologic synthetique," as Wohler had laid the 

 foundations of a "chimie synthetique," by his classical discovery 

 forty years before. 



* Japp, I. c. p. 828. 



f Rainey, G., On the Elementary Formation of the Skeletons of Animals, and 

 other Hard Structures formed in connection with Living Tissue, Brit. For. Med. 

 Ch. Rev. XX, pp. 4.51— i76, 1857 ; published separately with additions, 8vo. London, 

 1858. For other papers by Rainey on kindred subjects see Q. J. M. S. vi {Tr. 

 Microsc. Soc), pp. 41-50, 1858, vn, pp. 212-225, 1859, \Tn, pp. 1-10, 1860. 

 I (n. s.), pp. 23-32, 1801. Cf. also Ord, W. M., On Molecular Coalescence, and on 

 the influence exercised by Colloids upon the Forms of Inorganic Matter, Q. J. M. S. 

 XII, pp. 219-239, 1872; and also the early but still interesting observations of 

 Mr Charles Hatchett, Chemical Experiments on Zoophytes; with some observa- 

 tions on the component parts of Membrane, PhiJ. Trans. 1800. pp. 327-402. 



