24 Mr. Griffiths' Description, Sec. 



having the springs of sufficient length, a very large loop may be 

 made, and I should think without any fear of injuring the bladder : 

 if the calculus should be small, it may be drawn out through the 

 canula; if too large for that, it must have holes repeatedly 

 drilled, till it crumbles into pieces small enough. 



The principal advantages that this appears to possess over the 

 French instrument before alluded to, are, 



1st. Its form is better adapted to the urethra. 



2nd. It can be made of a smaller size. 



3rd. There is less chance of hurting the bladder with the bent 

 springs, than with the forceps. The loops will fix the stone more 

 securely, and if either of them should happen to be broken, both 

 the parts can be withdrawn through the canula, and a fresh spring 

 immediately adapted to it. 



4th. The fragments, or small calculi, will pass off by the 

 canula, without injury to the urethra ; this may be assisted by in- 

 jecting water, and letting it out again in a full stream. 



To destroy a calculus of any size would require the instrument 

 to be used a great number of times ; but however tedious, many 

 persons, I think, would prefer it to the dangerous operation of 

 lithotomy, and would resort to it at an earlier period of the^ dis- 

 ease, when the stone had not acquired much bulk, and the symp- 

 toms were not so urgent as to make immediate relief necessary. 



Bentinck-Street, August, 1825. 



Art. V. — Outlines of Geology, being the Substance of a 

 Course of Lectures on that Subject, delivered in the Am- 

 phitheatre of the Royal Institution of Great Britain, by 

 William Thomas Brande, F.R.S., Professor of Chemis- 

 try in the Royal Institution, fyc. 



[Continued from Vol. XIX., page 198.] 



IV. 



There are abundant difficulties in the way of any satisfactory 

 theory respecting the origin of the diluvial remains of quadrupeds, 



