INDUSTRI.4L A N D ENGINEERING CHEMISTRY
November, 1926
assistants t o meet whomsoever of note came t o his office. Young men usually have little opportunity t o meet prominent men. I recall with much pleasure having been called into his office, when 1 had been his assistant but a short time, t o meet Harvey W. Wiley. Jaffa was one of the charter members of the Faculty Club on the campus. H e still takes a n active part in the club. At noontime almost any day you may find him in the billiard room with a group of younger men engaged in a game. At home you will find Jaffa always cheerful and happy. No matter what difficulties and disappointments he has experienced during the day, he drops these behind when he leaves the campus.
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Adversities do not seem t o upset him. H e has a remarkable way of seeing the bright side of life. During the fire in the fall of 1923, which wiped out in a few hours so many blocks of Berkeley’s fine homes, Professor Jaffa lost his home and all but a few of his personal effects. His home was the last of eleven hundred to burn. I came upon him in his office in the evening after the fire and found him nervously playing with a pencil. He looked more tired than usual but otherwise appeared just the same as ever. He said “It feels mighty queer not t o have any place t o go home to, tonight-well, anyway Mrs. Jaffa won’t have to climb the hill any more.” HAROLD Goss
Poisoning b y Mercury Vapor’ By L. M. Dennis CORNELLUNIVERSITY, ITHACA, N. Y.
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T IS probable t h a t most of those who work with mercury
do not realize the menace t o which they are exposed through possible poisoning by the vapor of the metal, and they are also probably not aware of the insidious manner in which the vapor, entering the system through the lungs, will gradually cause most serious toxic effects. Perhaps several of our fellow-scientists have developed, in less or greater severity, the symptoms of mercury poisoning, and it is with the thought of enabling them to recognize the cause of their ailment, and of calling the attention of American chemists and physicists generally t o the gravity of this danger, t h a t this summary of a recent article2 by Prof. Alfred Stock, of Berlin, is presented. For the past twenty-five years Professor Stock has been working almost constantly with apparatus containing mercurypumps, manometers, valves, troughs, etc. Early in t h a t period he began t o suffer both mental and bodily distress, for which the eminent physicians whom he consulted could find neither cause nor remedy. The most marked symptoms were intermittent headaches, a t first slight and gradually increasing in severity, nervousness, catarrh, frequent sore-throat, weakening of the senses of smell and hearing, acid taste in the mouth, inflammation of the eyes, sore spots on the tongue and throat, reddening of the gums and toothache. These last two symptoms, which usually appear early in mercury poisoning, appeared quite late in Professor Stock’s case because, he thinks, of the great care t h a t he had taken of his teeth since early boyhood. Further symptoms were mental weariness, disinclination for work of any kind, sleepiness, trembling of the outstretched fingers, aching in the limbs and back, and loss of appetite. Particularly depressing was the weakening of his memory, which had formerly been unusually good. It became difficult for him t o lecture without very detailed notes before him, a telephone number was forgotten in the brief interval between looking i t up in the book and putting in the call, names escaped him, even those of old acquaintances, errors were made in the simplest of mathematical calculations, and the writing of an article or even of a n ordinary letter called for infinite labor. His assistants in his research laboratory suffered similarly. The cause of the trouble was not recognized until two of his co-workers, who used a small, closed room because of the nature of the investigation which they had in hand, developed a n acute, severe attack of mercury poisoning with the familiar symptoms of soreness about the teeth and ulcers on the gums, which made the cause a t once clear t o the attending physician. This led to the immediate examination of the air of the laboratory, which was found to contain mercury, the amount varying in different rooms between 0.01 and 0.001 mg. per cubic meter. 1
Received July 21, 1926.
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2. angrw. Chem., S9, 461 (1926).
Air at room temperature saturated with mercury vapor contains about 12 mg. per cubic meter. A man inhales hourly about 0.5 cubic meter of air, and most of the inhaled mercury is retained in the lungs. The fact t h a t t h e laboratory air contained only so small a n amount of the vapor explains why the symptoms developed fully only after one or more years. To avoid possible poisoning by vapor of mercury the floor of t h e laboratory should be free from cracks (it should not, of course, be of wood) and if covered with linoleum or oil cloth, breaks in the covering should be a t once repaired. No spilled mercury should be allowed t o lie in the room, and containers of mercury should be covered or stoppered when not in use. Ventilation should be thorough and efficient. (In a later article Stock and Heller describe a method for the detection of mercury in the air.) All work with open mercury should be carried on in a hood whenever possible. No medication thus far used appears to hasten the removal of mercury from the body. Only fresh air and time bring recovery. Professor Stock adds a warning against amalgam fillings in the teeth and gives the quantitative results of exposure of silver-amalgam, which had carefully been prepared by a dentist, to the temperature of the body for a period of some days. From 0.801 gram of such a n amalgam 11.2 mg. of mercury distilled off in 23 days; from 0.810 gram of amalgam, 15.3 mg. of mercury in 12 days. He cites cases of undoubted mercury poisoning caused by such amalgam fillings. In closing, he calls attention to the sufferings of Faraday during the last third of his life, which in the light of Professor Stock’s experience seem almost certainly t o have been due to poisoning by vapor of mercury. “It is tragic t o think how easily his ills might have been relieved, and what further gifts to science might have been made by this great Master if the cause of his distress had been recognized and removed.”
Suit over Cracking Patents Still in Process Editor of Industrial and Engineering Chemistry: M y attention has been called to a glaring inaccuracy on page 1045 of my article, “Progress of a Year-A Chemical Review,” in the October issue. The statement is there made that “during the fall of 1925 a lengthy trial of the Government’s suit against the oil companies charging illegal monopoly on the basis of the patents held on cracking processes dragged itself out through many weeks of expert testimony and recrimination from opposing witnesses.” As a matter of fact, the trial is still dragging itself out and the defense of the oil companies has just begun. The “recrimination” certainly occurred, but this was not between witnesses of the opposing sides in the controversy. D. H. KILLEFFER
