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INDUSTRIAL A N D ENGINEERING CHEMISTRY
Vol. 16, No. 11
WORLD-WIDE CHEMISTRY German Letter By Walter Roth C ~ T I I E N GERMANY .
GOLDFROM QUICKSILVER Dr. Miethe’s collaborator, Dr. H. Stammreich, gives in a recent number of Naturwissenschaften the first detailed information on the disintegration of the mercury atom. He reports the experiments that were conducted between the 6th and the 22nd of May with A. Jaenicke’s quicksilver lamp, and describes in full the apparatus used, the preparation of the burner, and the precautions necessary. In the quartz dish used (weighing 14 grams) there was no gold, but 6 X 10-6 grams of silver. As material for filling the lamp “Kahlbaum” quicksilver was used, and 2 kg. of this material contained 1.79 X 10-6 grams of silver and a very small quantity of gold, not enough to determine quantitatively. This quicksilver was subjected to slow distillation in vacuo. The distillate was free from gold, but still contaminated with traces of silver. A further distillation gave a material free from noble metal, of which 1.52 kg. were used in filling the lamp. The lamp burned for 197 hours without interruption. The electrode potential varied over an average arc of 158 mm. and a t a density of 12.6 amperes between 160 and 175 volts. The emptying of the burner after cooling was done very carefully, as experience showed that gold-carrying viscous droplets of quicksilver were fastened stubbornly to the walls. The mercury from the lamp was subjected to a careful and very slow vacuum distillation; from grams of gold were the last drops of quicksilver 8.2 X recovered. The experiments, of course, need severe tests. Professor Haber, after testing seventeen samples of quicksilver, which were given to him by Miethe and Stammreich, has been unable to detect gold. NEW FINISH FOR COTTON THREADS If cotton is treated with highly concentrated nitric acid in the presence of products formed by the action of nitric acid on cellulose, starch, or protein, a shrinking of the fabric takes place, but at the same time a crimping and roughening of the threads occur. The fabric so treated resembles in appearance and feeling more a woolen fabric than a cotton one. This new process, which was discovered by Ch. Schwartz produces a new form of finish to the cotton threads. According to information from Dr. Beil concerning this new process which is called “philanizing,” the threads so treated show a greater affinity for dyes as is the case with mercerized threads. Aside from the more beautiful appearance and the softer feeling of philanized threads, they are more durable. It is true that philanizing offers many difficulties in practice, as one must worke with highly concentrated nitric acid, so that it can only be carried out in chemical plants. The Hochster dyeworks, with their enormous plant for the production of nitric acid, have been operating the process for several months. The philanized material is then finished in the textile finishing works, the dyeworks, and the print works. Colored fabric whichis dyed with indanthene and other vat dyes, as well as yarn, loose cotton, or roving, can be philanized. It is thought that new articles of this material will be put on the market, which will occupy a place between the cheap cotton and the expensive wool. NEW PROCESS FOR PURIFICATION OF WATER By this new process the water to be purified is subjected to the influence of an electric current without the addition of any chemical. I n this way the electrolysis of all salts present in the water takes place, the basic and acid constituents migrating to the proper electrodes. Then follows the removal of these by electroosmotic means. The electrolytic cell is divided into three compartments by means of suitable diaphragms of fabric. I n the outer compartments are the electrodes; in the middle section, the water. The diaphragms are impermeable to water, but under the action of the electric current permit the basic and acid constituents of the salts to migrate to the proper electrodes in the outer compartment. From there they are removed by a continuous stream of rinsing
water. The water in the middle section becomes continually weaker in salt content as the action proceeds, until it is practically salt free and resembles a product equivalent to distilled water. Of course, if a water entirely free from salt is not essential, but only a soft water poor in salt, by lessening the duration of the ‘action of the current water any degree of hardness may be obtained. I n practice, where a continuous process is desired, instead of a three-cell apparatus a series of about ten cells is arranged in compact form. The assembled apparatus resembles a filter pressin arrangement. I n operating, the water to be purified flows into the middle chamber of the first cell, is automatically carried from there to the second, then into the third middle chamber, etc., and leaves the last cell in the desired degree of freedom from salt, or completely salt-free. E. Mayer and R. Schon have described experiments with this new water-softening process. According to them an apparatus at Vienna has been tested, and compared with distillation, the only process which gives a completely equivalent product, it gives a saving of 95 per cent. The apparatus has the advantage of small space requirement, ease of setting up and transportation, and the current can be shut off by means of a simple switch. Contrary to the chemical purification processes, which in general. give an alkaline water, the electro-osmotic process offers a completely neutral, chlorine and nitrate-free water.
POISONING BY FLUOSILICIC ACID Recently several cases of poisoning by fluosilicic acid and its salts have been observed. Already a dozen people have lost their lives in this way, as vermin exterminators and disinfectants, as well the use of fluosilicic acid as in industry, have become more and more common. Dr. Luhrig writes in detail concerning such cases of poisoning. On a farm a liquid was given to a maid by a neighbor for the purpose of ridding the place of bugs, and a small child drank of this and died within five minutes. The liquid was called “Kerman” and was obtained by the farm management as a disinfectant for fighting the hoof and mouth disease. Chemical examination gave a fluosilicic acid content of 22.5 per cent and 2.1 per cent aluminium oxide. This quick, strong poisonous effect of fluosilicic acid has apparently not been sufficiently well known, heretofore, for in the Prussian police regulations concerning the handling of poisons these acids are not particularly mentioned. Dr. Luhrig recommends, therefore, not merely warning against remedies of this kind, but mentioning them specifically in the regulations, in order that any carelessness in handling and storing may be prevented. COLORED BRASS Formerly it was impossible to obtain brass in colors. This has recently been accomplished, however, according t o F. Stahlenschmidt. The purified material is exposed to various baths of a binary electrolyte in electrolytic process whereby definite temperatures and exposure to light are produced in order to obtain the desired color. Whereas heretofore brass. objects could only be given a brown color, it is now possible to produce colors from bright yellow to orange, from red to blue, from blue-green to yellow-green, and even to produce a full gold color. This is not a colored coating, but the colors are produced in the metal itself and are extremely permanent.
LEIPZICFALL FAIR If the Leipzig Fall Fair may be used as a barometer for German industry, then it is in very bad condition just a t present. The peculiarly chemical industry was almost entirely absent at the last fair; buyers were present in small numbers, because they lacked the means to buy, and sellers had to press for quick payments. Much is expected of the next spring fair, as it is hoped that by then the conditions will improve and longer terms of payment may again be possible. Among chemical displays the stand of 13. Scheidemandel was notable for the glue pearls which. were put on the market for the first time. September 16, 1924 -
North China is one of the chief oriental markets for kerosene from the United States, which supplies by far the greater part of this commodity sold there.
