Show manufacturing glue it is generally made from the ears of oxen and calves and the tha parings of the hides skins ac the tho parings of ox and other hides make the strongest tron gest and afford about 45 per cent of glud giue the tha cuttings and parings of hides are first macer abed in milk at of lime in pits or vat vats and the liquor is renewed two or three times in the course of two weeks they are then tilen taken 0 out t with the ilme lime adhering to them thein and washed in water in baskets and are tilen then placed on hurdles to dry when exposed to the air whatever lime remal remains us on them is converted into chalk by absorbing carbonic ach gas gaa fram from the air A small portion of chalk will not be injurious for tile the after process although quick lime would the next process is the extraction of the gelatine or glue from the tim pieces of the skins shins ac 9 BO so treated for this purpose they are placed in a large bag bam or rather net made of thick cord and ard spread 0 open within abarge caldron A light framing bithia the caldron prevents the tha b bag ag from sticking 9 to its sides the water of the caldron is then gradually brought tip up to the boiling poin point t and as the prepared skins in the net gradually melt and mingle wa tho the water more are placed in the net ilet and the they are ara frequently stirred up and pressed with ales poles the condition of the caldron is is tested occasionally by taking out some of tile the liquor and setting it asile eslie to cool in a glss gloss when a clear mass r jolly is produced the boiling is judged to be sufficient me tie mou mouth h of tile the net is then closed with it its co rd and it is raised or air hoisted holsted lio iio isted above the caldron over a roller and left to irain iraln arain drain The Thet liquor of the caldron if not strong 0 enough to mike glue may be farther concentrated concentrate d by boiling the contents of the net are boiled 1 a 1 second time to make size and when wilen the solutions are too weak to make glue or size ilze they are economically no used instead of fresh water the gelatine liquid of tile the glue caldron ara drawn off iri iii into a vessel called a settling back which is surrounded with warm water and the temperature ls is kept up for about five hours to maintain it in t tha a liquid state until the solid impurities settle to the bottom the clear liquor is then drawn off into wooden coolers which are about six feet wide vide and two feet deep here it becomes a firm jelly which is 13 cut out into square cakes with a spade these are deposited in square cakes in iii a wooden box having slits in it through which a brass wire attached to a bow is brawn to cut it into slices these are placed on nets strat stretched ched in wooden frames and exposed to the air to dry they are frequently turned and careful carefully iv watched until they are about two thirds dry ahn they are removed to a room and they aro are mt to dry still farther and then they are finally dried ina lna a warm room the drying of the glue is an operation chieh requires great care and attention good glue should contain no pecks speck but be lie transparent and clear when held beld U up p to the he light the amber colored giue glue is the best kind far for cabinet makers black kind as a some suppose the tha best glue swells without melting when immersed in cid cold water and it renews its former alze size on drying the best method of son softening and dissolving glee for use is first to immerse it I 1 in ll 11 mall small pieces for at about out twelve hours in cold water then set it over a fire and gradually raise its temperature pera ture until it is all dissolved fine white glue is made from careful selections cf of white clean skin parings and there may be bleached in a degree by immersing them in a weak milk of chloride of lime instead of simple lime inne size for stiffening ning straw and leghorn hats is made mada of clippings of parchment and fine white sheep skin dissolved in boiling water white glue is employed in fit the sti stiffening frening or dressing used for silks and other oilier fabrics which are re dyed and re dref drep dressed sed if glue which has been steeped in cold water until it has swelled bo be then immersed in linseed oil and heated it dissolves and forms a glue of great tenacity which when dry resists damp glue glae ii is employed for making malting molds for ier castings in fa wax an and n plaster of paris mixed midd with molasses it form forms the ink rollers of the book printer scientific american |