38 
“Some further experiments on the Cohesion of Water 
and Mercury,” by Professor Osborne Reynolds, F.R.S. 
Two years ago I exhibited before this Society a vertical 
tube, 60 inches long and -/- 6 - inch in diameter, in which mer- 
cury sustained itself by its internal cohesion and adhesion 
to the glass to a height of 60 inches without any aid from 
the pressure of the atmosphere.* This tube was subsequently 
shown at the Royal Society and was submitted to inter* 
mittent observation at the College until about nine months 
ago when one day, on being erected, it either collapsed or 
was broken by the fall of the mercury. The fracture taking 
place simultaneously with the fall of the mercury, it was 
impossible to say which. 
This tube was of common German glass, such as is used 
for chemical purposes, and as it proved insufficiently strong 
I deferred further experiments until I could obtain a tube 
of greater strength. This led to considerable delay, but I 
have now a tube 90 inches long, in which mercury suspends 
itself in a water vacuum resisting a tension or negative 
pressure of three atmospheres. Although this is probably 
still far short of the possible limit, a certain amount of 
interest attaches to the probability that the tension in this 
tube is the highest to which any fluid matter in the uni- 
verse has been subjected. 
Since my former communication, in working both with 
the old tube and particularly with the new and longer tube, 
further experience has been gained of which it is my present 
object to give some account. 
During the year and nine months before the old tube 
broke no great change had been noticed in the water and 
mercury within the tube; the former became rather cloudy 
and the latter showed symptoms of a scum. These changes 
were but little noticed, as they did not apparently inter- 
fere with the suspension of the mercury. 
* Proceedings Lit. & Phil. Soc., 1877-8, p. 155. 
