Pure Mercury OTTO H . MULLER Cornell University Medical College, New York, Ν . Υ. Ι Ν Α recent article on this subject ( / ) , E. Wichers, of the National Bureau of Standards, has pointed out that the condi tion of the surface of mercury is a sensi tive measure of chemical purity. The presence of base metals in a concentration of 1 part in 1,000,000 is indicated by either the formation of a film or "tailing" of the mercury when it is shaken in a glass flask after having been dried. T h e following procedure, of equal simplicity and based on the same principles, might be used in stead of, or in conjunction with, the above. It serves to indicate the degree of progress during the purification of the mercury. The writer learned of this test in the laboratory of J. Heyrovsky in Prague but is not sure'that it originated there. Many may be surprised t o learn that pure mercury shaken with distilled water forms a fairly stable foam which dis appears gradually in from 5 t o 15 seconds. In contrast to this, very "dirty" mercury does not foam at all. Mercury which contains mere traces of impurities does foam when shaken with water, but the foam is stable for 1 or 2 seconds only and then collapses suddenly. Experiments performed in this laboratory have shown that the sensitivity of the foam test is of the same order as the procedure described by E . Wichers (1). For instance, an amalgam of 1 mg. of copper in 1 kg. of mercury will fail t o give a stable foam when shaken with distilled water. It should be pointed out that the distilled water must not contain any organic mate rial and that the flasks used must be scrupulously clean. A strip of litmus paper dipped for a few seconds into the water to determine its acidity will contaminate it sufficiently to prevent a stable foam with pure mercury. Whenever impurities are present, a film is clearly visible on the surface of the mercury.. While pure mer cury in contact with water has a mirror like surface, prolonged shaking usually produces a slight film, probably on account of the presence of carbonate. The foam test has proved of value in the following procedure for purifying mer cury for polarographic studies. The used mercury is first shaken with water in a heavy-walled separatory funnel. [If the mercury is very "dirty", air is sucked through the separatory funnel as de scribed by E. Wichers (1) ]. The lowest, cleanest portion of the mercury is then allowed t o fall through the ungreased etopcock in a fine stream of small drops into a heavy-walled flask or separatory funnel partially filled with a solution of nitric acid and mercurous nitrate. Next, the mercury is shaken with the acid for several minutes and drained through a separatory funnel, again in a fine stream
1528
of small drops, into a flask partially filled with distilled water. If some acid has come along with the mercury, a second washing with distilled water is necessary before a stable foam results when the mercury and water are shaken together. If no stable foam appears, further purifi cation with nitric acid is indicated. The scum retained in the funnel after each separation is collected in a special flask for further treatment. The mercury which produces a good foam with water is poured through a pin hole in a cone of filter paper and can be completely squeezed through this pin hole without leaving any residue on the paper. Such mercury, when dry, satis fies the purity test described by F. Wichers (i), and can be used directly for "pool" mercury anodes in polarography. Before the mercury is used for the dropping mer cury electrode, however, it is usually purified further by vacuum distillation to remove any noble metals which might lower the very high hydrogen overvoltage observed on pure mercury. Literature Cited (1) Wichers, E . , C H E M . E N O . N B W S , 2 0 , 111 1
(Sept. 10, 1942).
Drawback Provisions of 1942 Revenue A c t ' T ' H E drawback provisions of the 1942 Revenue Act relate to "distilled spirits" generally (whisky, brandy, rum, gin, etc.) and not "alcohol" exclusively. Such drawback privilege was conferred by an amendment t o Section 3250 of the Internal Revenue Code relating to special taxes. This does not give the Bureau of Internal Revenue much power to regulate business conducted b y the new class of manufac turers of the products mentioned in the new subdivision L of this section. Any manufacturer can pay the new special tax and, if he is able to procure the taxpaid distilled spirits, will be entitled to the drawback of $3.75 per proof gallon. Had the privilege been restricted to "alcohol" and conferred by an amendment of sub chapter C of the code relating to "indus trial alcohol", there would be abundant authority to regulate the manufacturers who could obtain the drawback and their business.
Flash of Genius Τ F you still have space to devote t o the "*· "Flash of Genius" (/) discussion, I think your readers will be interested in the following extract from page 491 of the "Report of the Commissioner of Patents for the Year 1849".
Errors Entertained Respecting Inventors is a prevalent opinion that both ordi IcostTnary and extraordinary inventions their authors little labor and thought to develop: nothing is more erroneous. It is an essential element of man's being and of the constitution of things under which he exists that all truths, mechanical or philosophical, can only be realized by strenuous and continued efforts Our per ceptive faculties are too obtuse, and hap pily for us it is so, t o apprehend them at a glance. In that case, they would b e hdd too cheap to be looked for and deemed worthless when seen. If inventions re quired no exertion t o discover, where would be their value? If virtue cost nothing, it would cease to be virtue. No fact is clearer than that man's destinies are in his own hands and that he alone can exalt and debase them. To rouse him to be faithful to himself is Nature's ceaseless care. With powers dormant in him and equal t o every exigence, she leaves him to exert them or not. She does naught for him that he can do for himself and has taken care that h e shall know nothing, have nothing, that h e does not strive for. It is common to hear ingenious men dis paraged by ascribing their best things t o lucky or random suggestions—whereas, though appearing fortuitous, they may always be traced to previous reasonings or reflections: sprouting seeds whose transient plantings had been little noticed and forgotten. They had never spruag up had they not fallen on soils prepared b y previous culture to receive them. Sparks set not sand on fire, nor do fruitful ideas germinate in barren minds. Flashes o f thought, like those of the electric fluid, may dart suddenly and unexpectedly, bat they are not less the regular effects o f inducing causes. Inspiration descends not in its highest or its lowest forms, but on those who seek to be inspired. It is not given t o man to perfect aught without tou, and seldom without longcontinued toil. The smith forges not a. ploughshare with a blow, nor is any new device, however simple, matured save b y repercussions of thought. "Nul bien sans peine" is a universal truth. C. L. PERKINS CHASE BRASS & COPPER C O . WATBRBURY, CONK.
October 13, 1942
Sulfur Trends in September
1942); 806 (June 25, 1942); 1234 (Oct. 10, 1942).
ALTHOUGH production of sulfur in " ^ September 1942 declined 1 per cent from the preceding month, the output in the first nine months of 1942 was 21 per cent greater than in the corresponding period of 1941, according to a statement released by the Bureau of Mines, U. S. Department of the Interior. Mine ship ments of sulfur decreased 11 per cent in September compared with August. Pro ducers' stocks were increased 1 per cent during September.
Adam Piret, formerly advertising manager of the Winthrop Chemical Co., has been made advertising and sales promotion manager of Hare Chemicals, Inc., Flemington, N . J. Erik K. Pfau h a s been appointed sales and expart manager. Hare Chemicals was a c quired recently b y the National Oil Products Co., and is being operated a s a wholly owned subsidiary.
CHEMICAL
(1)
AND
CHEM.
ENO. NEWS,
20, 523 (April 2 5 ,
ENGINEERING NE^S
H I G H VACUUM PUMPS — Mounted on Iron Base
MOTOR DRIVEN CAPACITY Evacuation Speed When Free Air per Operated Minute
Guaranteed Vacuum
Number Pump Stages
of
Duo-Seal Oil Required
Size of M otor
Motor Characteristics
Each
Large Capacity
A72-701-H A72-701-J A72-701-F
0.05 Micron 0.05 Micron 0.05 Micron
33.4 Liters 33.4 Liters 33.4 Liters
300 r.p.m. 300 r.p.m. 300 r.p.m.
2 2 2
650 ml. 650 mi. 650 ml.
\i H.P. ^ H.P. p . P .
110 Volts A.C.—60 Cycles 220 Volts A.C.—60 Cycles 110 Volts D.C.
$140.00 140.00 140.00
0.10 Micron 0.10 Micron 0.10 Micron
58 58 58
Liters Liters Liters
525 r.p.m. 525 r.p.m. 525 r.p.m.
2 2 2
650 ml. 650 ml. 650 ml.
} S H.P. Κ H.P. \A H.P.
110 Volts A . C . - 6 0 Cycles 220 Volts A . C . - 6 0 Cycles 110 Volts D.C.
S155.0O 155.00 155.00
21 21 21
Liters Liters Liters
450 r.p.m. 450 r.p.m. 450 r.p.m.
2 2 2
550 ml. 550 ml. 550 ml.
^ H.P. M H.P. \i H.P.
110 Volts A.C.—60 Cycles 220 Volts A . C . - 6 0 CVclcs 110 Volts D.C. *
S75.0O 77.50 80.00
I.argor Capacity
A72-702-B A72-702-C A72-702-D
