522 Dr. Mac Culloch on Vegetable remains 



result of silex injected in a state of igneous fusion. I know not 

 that it is necessary for the theory which offers this explanation, that 

 this solution shouW be admitted, since the existence of that theory 

 is not necessarily implicated in the universal proof of this suppo-- 

 sition. It will scarcely be asserted that substances of so tender a 

 structure as those I have described, substances so evidently involved 

 in siliceous matter while freely exposed to light and air, could have 

 undergone this change by any process of compression connected 

 with igneous fusion. Nor could any theorist invent a scheme 

 of this nature which should involve the remains of a land animal, 

 so fragile as is that chrysalis of an insect figured in the plate 

 No. 29, with so little change of structure. A watery solution 

 of silex seems so indispensible for this purpose, that it is super- 

 fluous to insist upon it. Of such watery solutions there are abun- 

 dant examples existing, examples which it is unnecessary to quote ; 

 but the instances under examination offer to our consideration views 

 still more wide and more interesting, however difficult their ex- 

 planation may be. It is plain on reviewing some of the cases 

 above described, that a process different from the tedious one of 

 infiltration and gradual deposition, must have produced the ap- 

 pearances in question. Neither the free disposition nor the forms 

 of the delicate vegetable structures could have been preserved during 

 so slow a process, nor could their colour have remained unaltered. 

 The loss of colour must have followed the death of the plant, and 

 the total loss of its figure would have resulted from the gradual 

 changes which it must needs have undergone during the continu- 

 ance of a process so tedious. The remains are in fact (if I may 

 use such an expression) embalmed alive. To produce this effect, 

 we can only conceive a solution of silex in water, so dense as to 

 support the weight of the substance involved, a soiution capable of 



