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of January, 1865, I sent a letter to the chairman of the 
microscopical section, stating my belief that the spiral 
appearances could be clearly traced to a mechanical action 
which the solvent exerted on the vegetable cell, and that at 
some future time I hoped to illustrate this to the members of 
the section. 
Since December last, I have subjected cotton during 
microscopical examination to a variety of influences in acids, 
alkalies, metallic solutions, iodine, and also gun cotton in 
varied proportions of ether and alcohol. Repeated experi- 
ments tend to confirm my disbelief in the existence of spiral 
vessels, properly so-called, either inside or outside cotton 
hairs. 
It would be difficult to explain, by means of drawings, 
how these pseudo spirals are created, and have, therefore, 
supplied a number of microscopes for the purpose of showing 
at the close of the meeting the actual appearances. 
Some of the gentlemen present have witnessed these 
experiments, but, for the benefit of those who have not, I 
shall attempt a brief explanation to enable them to compre- 
hend more readily what they will see under the microscopes. 
In order to observe the action of the copper solvent on 
cotton, place a few hairs about a quarter of an inch in length 
on a glass plate, and cover them with thin glass ; it is useful 
to rub a little beeswax on the glass plate, in such a manner, 
as will just support the covering glass to prevent too great a 
pressure on the cotton ; then arrange the cotton under the 
microscope with a power of not less than SOO diameters. 
The solvent should be applied by a glass pipette to the 
edge of the covering glass whilst the observer is looking- 
through the microscope (this is important). If the solvent 
is very strong, the action is too rapid for the eye to follow, 
if of moderate strength it will be seen that as soon as 
the solvent comes into contact with the cotton in the field 
of view, a rapid rotation or twisting of the hairs takes place. 
