Collodions are solutions of pyroxylin or soluble gun cotton with medicinal agents, for external application.
The next step was to cut loose altogether from the natural oils and use for the varnish a solution of some of the cellulose esters, usually the nitrate (pyroxylin or guncotton), more rarely the acetate.
Collodion, as I have explained in previous chapters, is a solution in ether and alcohol of guncotton (otherwise known as pyroxylin or nitrocellulose), which is made by the action of nitric acid on cotton.
It has made modern photography possible, for the film we use in the camera and moving picture projector consists of a gelatin coating on a pyroxylin backing.
Without going into the question of their variations and relative merits we may consider the advantages of the pyroxylin plastics in general.
To a saturated solution of tannic acid in alcohol and ether, in equal parts, add as much pyroxylin as the liquid will dissolve.
A tissue paper converted into a nitrogenous material (pyroxylin or dueppelpapier) by immersion in a mixture of sulphuric and nitric acid, and containing besides an insignificant proportion of wax and resin.
A viscid fluid formed by dissolving pyroxylin (Schoenbein's gun-cotton) in a mixture of ether and alcohol.
Saturate the pyroxylin with the alcohol, then pour in half a gallon of the ether, agitate for 3 or 4 minutes, and repeat the process in adding the remainder.
The weight of the pyroxylinought to be 375 grains.
Pyroxylin explodes, with a very sudden flash, and the development of very little heat, without either smoke or residue, at a temperature of about 300 deg.
Several modifications of pyroxylinare known, varying considerably in composition, though they all contain the elements of hyponitric acid, and are all explosive.
Pyroxylin is made by treating cotton with equal parts of nitric and sulphuric acids, then washing with water till the latter ceases to give a precipitate with chloride of baryta; then dry in the air.
Collodion is made by dissolving 5 grams of pyroxylin in the following mixture: Sulphuric ether, rectified 75 grams.
The quality of collodion differs according to the proportions of alcohol and ether and the nature of the pyroxylin it contains.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "pyroxylin" in a variety of sentences. We hope that you will now be able to make sentences using this word.
