4G2 Recent Improvements in Science. 



In the course of a week the mercury in the closed leg 

 rose a line, which might lead to the supposition that the 

 wax had not been so closely applied to the glass as to pre- 

 vent the existence of any capillary opening between the 

 wax and glass. To determine this point another equally 

 curved tube was taken, fused at one extremity, and filled 

 as before. To ascertain the smallest rise, a small mirror, 

 with a transverse scratch upon it, was placed between the 

 legs of the tube, close to the bent, leg ; so that the scratch, 

 when it cut the reflexion of the eye over the pupil, appeared 

 as a tangent to the upper surface of the mercury in the tube. 



On a small rise of the mercury, the eye must be brought 

 forward, when the scratch appears still to be the tangent 

 of the mercury, and passes immediately through the mid- 

 dle of the reflexion of the eye. 



After trial, it was found that a tube fused at one end, 

 and about a line in diameter, answered the desired purpose. 

 This tube was filled with water, and then a globule of mer- 

 cury, which occupied 07 line of the tube, was placed in 

 it; some pulverized sugar was dissolved in the water. 

 The tube was then made fast to the mirror, and placed ho- 

 rizontally, in order that the mercury might not be pressed 

 down by its own weight. The drop slowly progressed to- 

 wards the closed end of the tube. After the lapse of a 

 month, it had advanced about a line. The water which 

 was expelled, mixed itself with the sugar solution ; and 

 this was concentrated by evaporation, without depositing 

 any crystals. A solution of gum, substituted for that of 

 the sugar, gave the same result. In ten days, the drop of 

 mercury advanced 0-2 line towards the closed end of the 

 tube. 



The converse of this experiment was tried with a por- 

 tion of a straight tube, which was fused at one extremity. 

 A dense solution of sugar was placed between the closed 

 end and a drop of mercury ; and before the drop some wa- 

 ter was introduced. If the latter evaporated, it was re- 

 newed. The drop advanced towards the open end of the 

 tube, while the saccharine solution increased in volume by 

 the absorption of water. 



Extending his researches in this way, with different li- 

 quids, Jerichau draws six inferences from his experiments. 



