54 



ACTION OF LIQUIDS ON THE 



Bladder 

 shrinks in 

 contact 

 with brine 

 or alcohol. 



vanic apparatus) ; with the lining membrane of the 

 pods of peas and beans ; with the fine inner bark of 

 trees ; with the skin of grapes, of potatoes, of apples ; 

 with the inner membrane of the capsules of bladder 

 senna, &c. ; but animal tissues surpass all others in 

 efficacy. Besides their unequal affinity, they have 

 an unequal absorbent power for dissimilar liquids, 

 by which their action in causing change of volume 

 during mixture is strengthened. 



When a tube, closed with bladder, and filled with 

 water, is immersed in alcohol or brine, there is pro- 

 duced at all points, where the brine or the alcohol 

 comes in contact with bladder saturated with water, 

 a change in the properties of the bladder. When, 

 in the open pores, the alcohol or brine mixes with 

 the water already there, the absorbent power of the 

 bladder for the water is diminished ; a smaller vo- 

 lume of the mixture is retained than of pure water ; 

 that is to say, water flows out in the direction of 



the clay cells were steeped in water and brine, and placed in the 

 receiver of the air-pump, under a pressure of 8 lines of mercury 

 ( of an inch) for 24 hours. 



Under the ordinary pressure, and in air the cells absorbed 



Weight. Volume. 



Water. Brine. Water. Brine. 

 100 parts of clay cell I. 15'4 14'6 15'4 12'2 



II. 11-8 11-6 



In vacuo the cells of clay absorbed 



Weight. 

 Water. Brine. 

 100 parts of clay cell absorbed I. 16-5 16'8 



II. 13-8 13-8 



11-8 9-7 



Volume. 



Water. Brine. 



16'5 14'0 



13-8 11-5 



