RESIDUO-CAPILLARY ATTRACTION. 



213 



water was found to be transmitted in greater abundance. Common 

 treacle is a very convenient substance for experiments. 



Let us suppose then that the lower part of the endosmometer is 

 filled with treacle, and having a thin membrane tied over its mouth, 

 is immersed in water ; and let us suppose that the fluid is allowed 

 to ascend until the operation ceases. 



At this moment we may regard the capillary pore which traverses 

 the membrane, as communicating at its two extremities with fluid in 

 the same state of mixture as the fluid in the contiguous vessels, 

 there being a gradual transition from one end to the other. 



Let C1C1C2C2, be a portion of 

 the membrane, AiAiAsA^ one of 

 its capillary pores, with its axis at 

 right angles to the plane of the 

 membrane, communicating originally 

 with the water at A^A^, and with 

 the treacle at A^A^, but when the 

 fluid has reached its maximum al- 

 titude, communicating with the ^ 

 first mixture of No. (10) at AiA^, 

 and with the second mixture of 

 that No. at A2A2. 



Imagine the geometrical figure of the tube, (not its material) to 

 be produced both ways to D, and D^, and cut off" from each end 

 of the tube a distance AiBi, AiB^, equal to the tube's sphere of 

 sensible attraction. 



Since A^Bi, and A^Bi, are insensible, we may regard the fluids in 

 AiA^BiBi, and A^A-^BiB^, as in the same state of mixture as the 

 fluids in the contiguous vessels. 



Vol. V. Part II. E e 



