173 
that these limits are owing to the presence of air or some 
other minor disturbing cause, and are not, as seems to have 
been hitherto supposed, owing to the want of cohesion in the 
liquid. And it seems to me that the cohesion now found to 
exist occupies an important as well as interesting place in 
the properties of liquid. 
Appendix, 26th April. 
Previous Notices of the Cohesion of Liquids. 
Besides the hanging of mercury in small gauges, another 
phenomenon which has long been known, shows a small 
degree of cohesion in water ; this is, that water will rise up 
small tubes by capillary attraction as well in the receiver 
of an air-pump as in air at the ordinary pressure. This 
fact was shown before the Royal Society by Robert Hooke. 
Prof. Maxwell, in his Treatise on the Theory of Heat, 
p. 259, after commenting on the fact that water has been 
raised to a temperature of 356° F. without boiling, remarks : 
“ Hence the cohesion of water must be able to support 
1321bs. weight on the square inch.” From which it would 
appear that he recognises cohesion as a property of water, 
and considers that the possibility of raising the temperature 
above the boiling point is evidence of such cohesion, but I 
am not aware that he has anywhere given his reasons for 
such a conclusion. 
I am indebted to Dr. Bottomley for reference to a paper 
in the “Ann. de Chim. et de Phys. III., XVI., 167,” by M. F. 
Donny, in which M. Donny gives an account of experi- 
ments in which he found that columns of sulphuric acid 
could be suspended in vacuo to a height of T3m., about 50 
inches, showing a tension of about 7 inches of mercury, care 
having been taken first to remove all the air from the acid. 
M. Donny further describes experiments made with water 
in exhausted tubes, in which he showed the effect of cohe- 
sion by shaking the tube. M. Donny does not, however, 
appear to have thought of the plan which I adopted of 
