_Use._ Vesicating collodion is used as an irritant. No. 1 was introduced
in 1862, and has many advantages over the other two. Mr Tichborne thus
described the most effectual method of using it in the 'Pharm.
Journ,':--"The part upon which the blister is to be raised should be
painted with the vesicant to the desired extent, bearing in mind that the
blister produced always extends to about one tenth of an inch beyond the
margin of the space covered. Care should be taken to give a coating of
considerable thickness, and to ensure this result the brush should be
passed over and over again, until about 1/2 dr. has been used to the
square inch, or less when operating upon a tender epidermis. It is
desirable to place over the intended blister a piece of oil silk, or, what
is still better, a piece of sheet gutta percha, somewhat larger than the
surface painted, as this will stop the exhalations of the skin, and so
render it moist and permeable. In ten minutes, or a quarter of an hour if
the cuticle is hard, the collodion should be wiped off with a little
cotton-wool moistened with ether, when the blister will almost instantly
rise."
=COL'LOID.= See DIALYSIS.
=COLLYR'IUM.= [L.] In _medicine_ and _pharmacy_, a topical remedy for
diseases of the eye. Formerly the term collyrium was applied to any
medicament employed to restrain defluxions.
=Collyr'ium, Dry.= _Syn._ EYE POWDER; COLLYR'IUM SIC'CUM, L. _Prep._ 1.
(Dupuytren.) White sugar, 1 dr.; red oxide of mercury, 10 gr.; oxide of
zinc, 20 gr.; mix.