Rainey^ on A7^tificial Calculi. 
49 
and it is exceedingly probable that a process very similar to this 
frequently takes place in living structures, and that many of the 
facts presented by the molecular disintegration of living tissues, 
and usually attributed to the direct influence of a vital force, are 
the immediate effect of a mechanical agency. One thing is 
certain, that where the conditions necessary for the operation 
of physical forces upon the molecules of matter are present, 
whether in organic or inorganic substances, these forces do act 
either effectively or ineffectively. Vitality may oppose, modify, 
or direct their operation ; but there is no reason to believe 
that it ever either creates or annihilates them. The force of 
gravity, or universal attraction, would want its most distin- 
guishing attribute,, if every molecule in the universe were 
not, at all times and in all places, under its influence ; and 
it is illogical to suppose that in the case of vital organisms 
a distinct force exists to produce results perfectly within the 
reach of physical agencies, especially as in many instances 
no end could be attained were that the case, but that of 
opposing one force by another capable of effecting exactly 
the same purpose. 
For a fall discussion of the question of molecular coales- 
cence, as applied to the hard structures of animals, I must 
again refer to my former paper in the ^ British and Foreign 
Medico- Chirurgical Review;^ but from what has just been 
stated, it would be unreasonable to conclude that this process 
ends there, and that the skeletons of plants, as well as all soft 
structures, both animal and vegetable, are not equally under 
its influence. Many considerations appear to me to justify 
the inference that the constituent materials act upon one 
another, and are acted upon by the physical forces in the 
same way in plants as in the shells of animals. And as to 
the effect of coalescence on the molecules composing soft 
structures, it must of necessity be the same as on those of 
hard ones, unless it be a fact that the physical laws which 
act upon matter in a feeble state of cohesion, are not the 
same as those laws which act upon it when this force of co- 
hesion is augmented. It is true that the process of coales- 
cence in soft structures does not admit of that rigid demon- 
stration which it does in hard ones, in consequence of its 
being in the latter so slow and gradual as to afford ample 
opportunities of our observing it through all its stages, 
whilst in the former it would take place too suddenly to 
leave any traces of the precise manner in which it had been 
effected. And most probably the real nature of this process 
would never have been understood if it could not have been 
demonstrated on artificial products; for although there are 
evidences of its real nature in the calcifying shells of crusta- 
