Best Cement for Jars (Preserving)

You read that title right. "Cement" for jars had me smiling. In Miss Leslie's New Cookery Book ©1857  pg.645 she gives instructions on a substance for sealing canned foods, like wax on home-made jellies today. Today the idea of cement covering and protecting our perishable food doesn't sound appetizing however to those living in the 19th century it was practical and descriptive of the function it did. Below is the excerpt from Miss Leslie's book:

THE BEST CEMENT FOR JARS.—Before preserving and pickling time, buy at a druggist's, two ounces of the clearest and whitest gum tragacanth. Obtain also two grains of corrosive sublimate, (indispensable to this cement), and having picked the gum tragacanth clean, and free from dust and dark or discolored particles, put it with the sublimate into a very clean yellow or whiteware mug that holds a small quart and has a closefitting lid belonging to it. Then fill the vessel more than two-thirds with very clean water, either warm or cold, and put on the lid. Let it rest till next morning. Then stir it with an unpainted stick, that will reach quite down to the bottom. Repeat the stirring frequently through the day, always replacing the lid. In a few days the cement will have risen to the top of the mug, and have become a fine, clear, smooth paste, far superior to any other; and, by means of the corrosive sublimate, it will keep perfectly well to an indefinite period, if always closely covered, and having no sort of metal dipped into it. On no account attempt to keep this paste in tin, or even in silver. Both paste and metal will turn black and become spotted. Remember this.
Whan going to put away your sweetmeats or pickles, this paste will come into use, and be found invaluable. It is best to keep all these things in small jars, as opening a large jar frequently, may injure its contents by letfing in the air. In a large family, or where many pickles are eaten, those in most frequent use may be kept in stone-ware jars, with a wooden spoon always at hand for taking them out when wanted. On the surface of every jar of pickles, put one or two table-spoonfuls of salad oil, and then cover the top of the jar closely with a circular piece of bladder or thin leather. Next cut out a narrow band of the same, and cement it on with gum tragacanth paste, (made as above), and let it remain till you open the jar for use.
For sweetmeats, have glass or white-ware jars. Lay on the surface of each a circular paper, cut to fit and dipped in brandy. Next, put on an outside cover of bladder or thick white paper secured with a band of the same, coated with tragacanth paste. When this cement is used, the jars will not be infested with ants or other insects, the corrosive sublimate keeping them out.
This paste should be at hand in every library or office, when wanted for papers or books. It requires no boiling when made, and is always ready, and never spoils. For a small quantity, take an ounce of the best gum tragacanth and a grain of corrosive sublimate. Get a covered white or yellow-ware mug that holds a pint; such a mug will cost but twelve cents. Dissolve in less than a pint of water.