ON THE EARLY STAGES OF INFLAMMATION 261 
movements of the lashing filaments. It is evident, however, that in order to 
produce effects at all comparable to the state of the tissues of the frog’s web 
in congestion, it would be necessary to adopt some more delicate method of 
experimenting, and the most eligible means for this purpose seemed to be to 
allow an irritating vapour to play upon a ciliated surface. Accordingly, on 
the 30th of November, 1857,' having cut off a small piece of the tongue of a frog 
killed about an hour before, and placed it upona slip of glass under the micro- 
scope, with just enough water to permit the free play of the cilia, I held near to it 
a piece of lint soaked in chloroform, keeping my eye over the microscope. The 
effect was instantaneous cessation of the previously rapid action of the cilia, 
which now stood out straight and motionless, like the hairs of a brush. I now 
immediately withdrew the lint, after which the same state of complete inaction 
continued for about half a minute, when languid movements began to show 
themselves, and after the lapse of five minutes more the ciliary action was going 
on pretty briskly in some parts, and ten minutes later seemed to have almost 
completely recovered. 
Thus chloroform vapour produced in the ciliated epithelium-cells a con- 
dition precisely similar to that brought about in the pigment-cells by irritants 
applied so as to cause inflammatory congestion of the web, viz. a state of sus- 
pension or temporary deprivation of functional activity. And as the removal 
of the epithelium-cells from the surface on which they grow does not arrest the 
movements of their cilia, no mere paralysis of nerves could account for this 
result, which necessarily implied that the epithelial tissue itself was affected 
with loss of power to discharge its accustomed functions. In repetitions of 
this procedure upon the same and other portions of the tongue, I did not 
generally get complete cessation of movement of all the cilia, but usually some 
retained a languid action, which improved after the chloroform had been re- 
moved. In one instance, however, the same perfect stoppage took place as in 
the first case, and the recovery was also very general, though the returning 
action was languid. Under these circumstances, a piece of lint dipped in 
strongest liquor ammoniae was brought within about 14 inches of the object, 
and retained there for about fifty seconds, during which time the ciliary motion 
became progressively and greatly diminished, and within twenty-five seconds 
of the removal of the lint, had ceased altogether. Some water was then added, 
so as to get rid of the absorbed alkali, when the cilia soon began to move again, 
and within about three minutes their play was more vigorous and general than 
before. the ammonia was used, and three minutes later it was universal, as it 
was prior to the application of the chloroform. On another occasion, in a 
' This date indicates that the experiments on the cilia have been performed since the paper was read. 
