The objection to all such continuous or automatic arrangements is, of course, that the condensed water contains all the free ammonia that may have existed in the water originally, but it is only in cases where the water is exceptionally impure that this disadvantage will become really serious. The method here outlined has, no doubt, occurred to many, and may probably be in regular use, but not having seen any previous mention of the idea, I have thought that it might be useful to some pharmacists who prepare their own distilled water.—Phar. Jour.
COTTON SEED OIL.
"Cotton seed oil," said Mr. A.E. Thornton, of the Atlanta mills, "is one of the most valuable of oils because it is a neutral oil, that is, neither acid nor alkali, and can be made to form the body of any other oil. It assimilates the properties of the oil with which it is mixed. For instance, olive oil. Cotton seed oil is taken and a little extract of olives put in. The cotton oil takes up the properties of the extract, and for all practical purposes it is every bit as good as the pure olive oil. Then it is used in sweet oil, hair oil, and, in fact, in nearly all others. A chemist cannot tell the prepared cotton oil from olive oil except by exposing a saucerful of each, and the olive oil becomes rancid much quicker than the cotton oil. The crude oil is worth thirty cents a gallon, and even as it is makes the finest of cooking lard, and enters into the composition of nearly all lard."
A visit to the mills showed how the oil is made. From the platform where the seed is unloaded it is thrown into an elevator and carried by a conveyor—an endless screw in a trough—to the warehouse. Then it is distributed by the conveyor uniformly over the length of the building—about 200 feet. The warehouse is nearly half filled now, and thousands and thousands of bushels are lying in store. Another elevator carries the seed up to the "sand screen." This is a revolving cylinder made of wire cloth, the meshes being small enough to retain the seed, which are inside the cylinder, but the sand and dirt escape. Now the seeds start down an inclined trough. There is something else to be taken out, and that is the screws and nails and rocks that were too large to be sifted out with the sand and dirt. There is a hole in the inclined trough, and up through that hole is blown a current of air by a suction fan. If it were not for the fan, the cotton seed, rocks, nails, and all would fall through. The current keeps up the cotton seed, and they go on over, but it is not strong enough to keep up the nails and pebbles, and they fall through. Now the seed, free of all else, is carried by another elevator and endless screw conveyor to the "linter." This is really nothing more than a cotton gin with an automatic feed.
"HULLER" AND "HEATERS."
Then the seed is carried to the "huller," where it is crushed or ground into a rough meal about as coarse as the ordinary corn "grits." The next step is to separate the hulls from the kernels, all the oil being in the kernel, so the crushed seed is carried to the "separator." This is very much on the style of a sand screen, being a revolving cylinder of wire cloth. The kernels, being smaller than the broken hulls, fall through the broken meshes, and upon this principle the hull is separated and carried direct to the furnace to be used as fuel. The kernels are ground as fine as meal, very much as grist is ground, between corrugated steel "rollers," and the damp, reddish colored meal is carried to the "heater."
The "heater" is one iron kettle within another, the six inch steam space between the kettles being connected direct with the boilers. There are four of these kettles side by side. The meal is brought into this room by an elevator, the first "heater" is filled, and for twenty minutes the meal is subjected to a "dry cook," a steam cook, the steam in the packet being under a pressure of forty-five pounds. Inside the inner kettle is a "stirrer," a revolving arm attached at right angles to a vertical shaft. The stirrer makes the heating uniform, and the high temperature drives off all the water in the meal, while the involatile oil all remains.
In five minutes the next heater is filled, in five minutes the next, etc.
Now there are four "heaters," and as the last heater is filled—at the end of twenty minutes—the first heater is emptied. Then at the end of five minutes the first heater is filled, and the one next to it is emptied, and the rotation is kept up, each heater full of meal being "dry-cooked" for twenty minutes.