﻿384 



M. G. Quincke on the Capillary Phenomena 



The column headed a ou cos co ou shows that the angle co ou was 

 very small or 0° only in experiments 3 and 4 of the second 

 series when based on the value 4*256 milligrammes for a ou formed 

 from observation of the drops (Table X. § 10). Since the liquids 

 become mixed in the course of time, and the angle w changes 

 with the time, as was evident from observations with flat drops, 

 the different values of the angle co ou in the various experiments 

 are not surprising, since, both in this case and in the experi- 

 ments of Section III. (§§ 16 to 18), the friction of the liquid 

 and capillary meniscus in the capillary tube materially influence 

 the elevation h u , to which the lower liquid rises above the com- 

 mon level, and make it too small. 



The form of the meniscus and of the angle co ou of the common 

 capillary surface appeared to me also to depend on the rapidity 

 with which the liquids rose in the capillary tubes. This rapidity 

 is itself dependent on the length and breadth of the submerged 

 capillary tube, and on that part of it which is filled with air. 



By shifting the capillary tube in the caoutchouc rings the me- 

 niscus was brought into other places of the tube, but without 

 producing any material influence on the magnitude of h u . 



21. A series of similar experiments was made on water and 

 olive-oil, oil of turpentine, or petroleum, all of which liquids have 

 smaller capillary constants and lower specific gravities than water. 



The meniscus of the common surface turns the concave side 

 upward when oil is above and water below, and the convex side 

 upward in the converse case. 



Above each series of experiments is given that value of a ou 

 for the common surface of the liquids o and u, which was ob- 

 tained from the observations on flat drops (Table X. § 10), and by 

 means of which the angle in the last column above (# OM = 180° 

 — Mou) was derived from the numbers in the penultimate column. 



Table XVIII. — Elevations in Capillary Tubes. Two Liquids 

 Petroleum above ; Water below. 



<r = 0-7977, cr M =l, 



2« = 5132 mgrms. « 0M = 3*834 mgrms. 



No. 



2r . 



h . 



hu. 



'S.rha. 



aou COS (liou- 



OiOU- 



1. 

 2. 

 3. 



millim. 

 0-245 

 0-208 

 0-227 



millims. 



6-9 



14-5 



15-5 



millims. 

 69-2 

 452 

 395 



mgrms. 

 9-158 

 5-914 



5-887 



mgrms. 

 2013 

 0-391 

 0-377 



O / 



58 31 

 84 9 

 84 21 



