34: HISTORY OF BRITISH ZOOPHYTES. 
gratify some ladies who were fond of natural science, I put 
a little iodine into a small phial, and having corked it, I 
thought, before giving it to the ladies, that I would try 
whether it answered my expectations; so, holding it in the 
flame of the fire, I soon had the pleasure of seeing the 
little bottle filled with the violet* fumes. The vapour dis- 
appeared so soon as the phial cooled. This I expected: 
but observing that there was a deposit on the glass inside, 
I applied a pretty powerful pocket-lens to it, and was de- 
lighted to find that the deposit which dimmed the glass 
consisted of beautiful dendritic crystallizations very much 
resembling those moss-like figures which I had admired on 
the Irish limestone. This is an experiment which, with the 
same enclosed particles of iodine, may be repeated as often 
as you choose; and on every repetition there will be a new 
set and arrangement of figures, like the numberless changes 
that take place on shaking a kaleidoscope. 
When theories are plausible, they often keep their ground 
for a considerable time in the minds of many, even after 
accurate observers have become acquainted with the truth, 
and have ventured to publish it. The light of truth on 
this subject began to dawn about the close of the sixteenth 
* Todine takes its name from the Greek word for a violet. 
