120 Dr. Front's further Remarks on Messrs.Tiedemann 



not exist in cork. My explanation is this ; cork is elastic, and 

 by the pressure of the sea is readily condensed, and conse- 

 quently much diminished in bulk, first that part out of the 

 bottle where the sides are not protected by the neck, and then 

 gradually the remaining length until the cork, separated en- 

 tirely from the glass, affords a free passage for the water, un- 

 less the sealing or wrapper be of such a tenacious and ductile 

 nature as to adhere to the glass and the cork so as to fill up the 

 space that would otherwise be left, and yet not yield com- 

 pletely to the pressure ; if it be brittle, it either separates from 

 the glass, or cracks, or both, allowing a free passage to the 

 water. Even pitch when cooled in the deep water would be 

 very brittle and crack or separate from the bottle readily, and 

 it would resume its former ductility and appearance upon re- 

 turning through the warm surface : this and similar considera- 

 tions will show how a trifling difference in closing the bottles 

 may produce considerable differences in the results of the ex- 

 periments. I remain, yours truly, 



2, Mead Place, Lambeth, July 12, 1828. J. DE C. SoWERBY. 



XX. Some further Remarks on Messrs. Tiedemann and 

 Gmelin's Observations on the Acids of the Stomach. By 

 Wm. Prout, M.D. RR.S* 

 f TVHE observations of Messrs. Tiedemann and Gmelin on 

 -*- my paper published in the last Number of the Philoso- 

 phical Magazine and Annals, seem to me to be intelligible 

 only on the two following assumptions. First, that the method 

 employed was adopted at random and without any preliminary 

 inquiry, and was intended to include every possible case ; and 

 secondly, that on the faith of this random method, / denied 

 generally and under all circumstances the existence of every 

 other acid except the muriatic acid, in the stomachs of ani- 

 mals. Now whether these assumptions can be fairly drawn 

 from my paper, I, as an interested individual, can scarcely, 

 perhaps, be admitted as competent to decide ; but I can truly 

 say at least, that I never intended that such inferences should 

 be drawn, nor was aware that any thing had been stated to 

 authorize them. 



With respect to the first of these assumptions it may be said, 

 that the nature of the gastric fluids, and especially the acid, had 

 occasionally occupied my particular attention for many years ; 

 and that during the summer before my paper was published, 

 I had set about the inquiry in earnest, and with the determi- 



* Communicated by the Author. 



nation, 



