The Birmingham age-herald., 1912-11-17

eamphor comes from the press in tho l form of dry cakes something over q 1 foot square and three quarters of an inch thick. Now, for the first time. the pyroxylin is dry enough to burn although in this condition 1t is not ex- tremely inflammable.
 The next process consists in break ing up these cakes. The cakes after being broken up are mixed with alco- hol coloring matter and sometimes oil. Wood alcohol is generally used. This mixture is then put through rolls or grinders similar to those used in rub her manufacture. The rolls are slight ly heated by steam and revo1ve slowly and the mixture is fed in by hand.
 After going through these rolls sev- eral times the celluloid comes out plastic, homogeneous mass. As now manufactured, however, there is almost no chance for any acid to remain after the numerous washing processes. Af- ter rolling the celluloid is pressed in steam-heated presses, and then cooled under pressure. temperature of about 72 degrees is used, and all tho remaining alcohol and air bubbles are driven off at this time. This leaves it in the form of thick blocks, the usual size being about 50 by 20 by inches.
 The blocks are next sheeted in n blaming machine. which cuts them into sheets of any desired thickness. The sheets are then dried, this being us- ually accomplished by hot air, After being dried and aged the sheets are polished by placing them between thin sheets of burnished metal and subjecting them to heavy pressure in 2 steam heated press. The sheets are then ready for shipment
 The product obtained by these pro- cesses is tough, somewhat elastic sIxe.4s ....l.a or of any desired color. It can be mad. 10 resemble ivory, bone and shell and is used as a substitute for all of these substances. 1t is slightly heavier than water and varies in density according to the amount of coloring matter in- troduced. It takes fire readily and burns fercely with a rustling, oil-like flame.
 When on fire in small quantities 1t is readily eXtinguished with water. As 1t is Of a waterproof nature and contains large amount of oxygen, 1t is somewhat more difficult to extin- euish than substances that absorb wa ter Dr. Won Schwartz goes as far as to say that water is of no use in ex- tinguishing celIuloid fire, but this is certainly not true of small quantities of celluloid. Sand appears to be much more effective than water. however.
 Explosive Qualities
 There has always been great differ ence of opinion in regard to the explos- I've qualities of celluloid Dr. Von Schwartz states that 1t decomposes hat 2S4 degrees F. and explodes at 3s3 de- grees F. It is evident that it would be difficult to heat 1t to 3SS degrees F. if 1t decomposed at a considerably low- CT temperature.
 It appears that at ordinary temper a ft oon he doH nj k friction or percussion, but that the gases given off when it decomposes arc explosive at high temperature. and it is this fact that has probably caused the widespread impression that cell luloid is explosive. An explosion night occur when q large quantity is burning owing to the gases given off
 Any combustible dust if very finely divided and mixed with the proper pro- portion of air can be exploded by flame, and the dust of celluloid, which is very combustible, Is especially ex- plosive under these conditions. Cellu- ibid is not soluble in most acids, but is soluble in glacial acetic acid and in warm, weak sulphuric or nitric acid | It is also soluble in fusel oil. In ether or alcohol the camphor is dissolved cut.
 The alcohol is largely evaporated in the drying processes through which 1t goes ana what llttie IS lett gradually eyaporates so that there is practically no alcohol in old cel1uloid. Camphor Is slightly volatile and this also slowly evaporates from celluloid, though much less rapidly than the alcohol. The pe- culiar smell of celluloid Is due largely to the volatile carnphor
 Celluloid is usuaiiy sold in sheets about 20x25 inches and of varying thickness from one-thousandth to two tenths of an inch Sheets of this size packed closely together weigh about 50 pounds to the inch, It is usually ship ped in boxes about five inches thick and weighing 200 pounds to 300 pounds It Is also sold In the form of rods. a usual size being Ax5 inches. Prices range from 75 to 90 cents pound scrap celluloid is worth about 20 cents a pound.
 The thinnest sheets are usually mounted on paper and then cut up as desired. The thicker sheets are used for making combs, novelties, etc. and arc stamped out with knives or dies The manufacture of combs Is perhaps the principal use to which celuloid Is put in New England, although consid- erable quantities are used in papeterie ano novelty works. jewelry factories etc.