thermoc~iupleinserted through at1 openiug in its f r f ~end, ~~t and tho tenipcrature of the vitreous and crystalline arsenic trioxide zones of the condensing tube by means of two thcrmocouples, the junctions of which were placed between the eondensing tube and the outer g l m tube, midway of the respective zones. A sketch of tlie apparatus is shown in Figure 2. I'KOCEDURE-The muffle and the two sections of the condensing tube were heated to tile desired temperatures and the vacuum pump was regulated to give tlie desirod rate of Aou: of air t,hrougli the apparatus. The iron pan, contaiuiug 50 grams of the black dust (the same material as used in the pre\-ious experiments), was iutroduced into the muffle and tlie muffle door closed. The t.emperatiire of tlie mufflc was maintained a t 500OC. and that of t,he crptalline arsenic trioxide zone a t 200°C. in all experiments. As soon t,he volatilization of tbc arsenic trioxide had stopped, which was in about an hour in all cases, tire pan was removed and the different condensation products were removed, weighed, and analyzed. EXPERIMENTAL YATh--The data are giveii in Table 11. There were three variables-the tempernt.ure of the zone of the condensiog tube in which the vitreous deposit was condenscd, the volume of air used, and the number and lengtii of tubes in the vitreous zoue of the conrlensiug tube (surface available for the condensation of tlre vitreous deposit). The temperature of the vitreous zone was 350°C. in the first set of experiments and 385O.C. in tlie second set; an attempt was also made to carry out some experiments at 325" C.,bot tlierewss so much coudensation a t the connection between tlie muffle and the condei~singtuhe that it became clogged. In the first aid second sets of experiments Dine small glass tubes 25.4 em. (10 inches) long (sufficient to fill a IO-inch section of the condensing tube) were placed in the vitreous zone of the condensing tube. The third set
OUTINE analysis filtrations often have to be carried out in large numbers. A long 12-unit funnel rack is usually available for such work, and the operator is
R
dependent upon overhead shelves to furnish sufficient head for wash solutions. In many laboratories where several analysts have to he accommodated the space available for such operations is very limited. With the object of insuring great,er facility iu laboratories of limited space and independenoe of built-in equipment, the accompanying filtration stand w&s desigiied. The filter stand consists of the following part~sas illustrated: (1) A cast-iron base 8 i d i t s in diameter and 2 inches hixh, with a perpendicular rod 1 1 2 by 36 inches (2) A metal tube which slips over the iron rod, rests upon a thrust baU-bearing within the cast-iron base, and extends about two-thirds the hcisht of the rad. (3) A boltom ihiielf 24 inches in diameter which carries two sets 01 twelve beakers iu concentric arrangement. ( 4 ) A middle sheli 18 inches in diameter with two l2-unit sets of holes oil the pcripliery which carry twelve filtcr funnels each. (5) A top shelf 12 inches in dianictcr provided with two large hales for holding two wash bottles.
The first two shelves are fastencd by means of set screws 1
Received Ociohei 20, 1927.
w:w similar to the first except that tlie titlies were orily 12.7 em. (5 inolres) long. Eacli set consisted of three indtvidual exporiineuts, in which tbrce different. volumes of air were drawn througli the apparatus. The results of these experiments corroborate those on t,be smaller scale as to the effect of the rate of flow of air through the apparatus. They do not indicate that increasing the temperature of the vitreous zone of dlle condeiising tube above 350°C. is of any advantage, but rather tliat it is harmful. A comparison hetwecu tlie experiments of sets 1 arid 3 shows that a large surface for tlrc condensation of vitreous arsenic trioxide is advant~ngeous, Summary
1 ~ ~ - 1 1the 1 refiuing of arsenic trioxide by volatilizatioo it was not found possible to prevent tlie vulatiliest,ion of a Imge portion of antimony present in the material being refined. It was possible, however, to conceiitrate the major portion of the volatilized antimony in a small amount, of arsenic trioxide (10 ty 30 per cent Sb) in tliat portion of the flue (condensing tube) nearest the furnace. Seventy to eighty per cent of the arsenic in the black dust was ubdained as a pure arsenic trioxide further along the flue. &Segregation of the autiinouy in a sinal1 part of tire arsenic trioxide was accomplislied by carefnl control of the temperatures of the furnace and flue, and regulation of the volume of air d r a u ~ through i them. 3.-For the best results the tcinperature of the flue near the refining furnace should be about 350" C., as much surface 8s possible should be provided for the condensation of the vitreous deposit, and the volume of air drawn through the system should he as small as possible. 4-The temperature of the furnace is apparently not so important except in so far ns it affects tbe temperature of the fliie,
to the slipover tube, aild revolve ibs a unit. The third shelf is fastened to the rod in the same manner and is a d j u s t a b l e . T h e m i d d l e shelf is also adjustable as to height over the slipover tube length. A D VA N T A GI-;&It occupies about onet h i r d of t h e borrcli space required by t.he ordinary rack of same capacity, and may be set upon an ordinary laboratory stool. It consists of riue unit a s s e m b l y f o r t w e l v e precipitates, twelve receivers, and t w e l v e f u n n e l s together with washsolutions, and i t may be easily t r a n s p o r t e d Rotary Filter Sfand
IXDUSTRIAL AND ENGINEERING CHEMISTRY
January, 1928
from place to place in the laboratory to obt:ain the best condition of light, heat, and ventilation. When not in use it furnishes shelving space for three dozen assorted beakers and twenty-four funnels ready for immediate use. The reserwir shelf makes the washing of precipitates inde-
101
pendent of permanent shelving for gravity flow, and does away with the ordinary wash bottle. It permits easy access to all parts from a sitting posture, insuring comfort for the manipulation in case of long-continued filtration and washing.
NOTES AND CORRESPONDENCE Device for Maintaining Flame Height in Sulfur Determinations
the presence of finely divided nickel a t temperatures of 200” C. and less. By varying the temperature and catalyst they also produced other specific crude petroleums. Consequently they advanced the extremely plausible theory that water in contact with carbides in the earth’s deep or comparatively deep crustlayers generated the requisite acetylene and, also, acting on Editor of Industrial and Engineering Chemistry: alkali metals or compounds, such as could most reasonably be I n the recently published Report of Committee D-2 of the inferred to exist in quantity a t different levels, was decomposed, A. S.T. RI. the members of Sub-committee VI1 on Sulfur Deterthe two reactions thus furnishing the requisite hydrogen and mination and Differentiation call attention t o the difficulty of acetylene. maintaining the flame at the prescribed height. Geologically speaking, the water could get down to the carbide The writer has found the device described by Squire [ J . SOC. and alkalies through fissures made by faulting and the oils Chem. Ind., 45, 4661’ (1926) ] t o be of great value u here accurate generated could ride back up the same way on water, being flame-height adjustment is required during trapped a t intervals under water pressure by further intermittent sulfur determinations, especially in a study slippings of the measures along the fault cracks and by the sealing of the effect of rate of burning, etc., on the of the vents by impervious top, bottom, and side formations, accuracy of such determinations. while the uncombined or otherwise combined gases could also The device is briefly as follows: By filling ascend with pressure incident to their creation or with water the wick tube with glass wool and having pressure. trimmed the wick flush with the top of the As tending to account, a t least in part, for the fate of the oxygen tube, any flame from 2 cm. in height to a released, the interesting fact may be mentioned that within the mere flicker can be obtained with natural last year or so a great oil well has been brought in in Colorado A = wick tube gas gasoline in the lamp. The novel feature a t a depth of about 4000 feet in which the gas accompanying the = rubber ring is that the flame can be kept a t a definite oil was not, as usually, a hydrocarbon, but was carbon dioxide C = 13-mm.length o f closely fitting height from the beginning of a burning, in enormous quantities and under enormous pressure. without interruption of the test, by raistubing S. A. HOBSON ing or lowering the small length of tubing
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A
AMOKY, MISS. October 24, 1927
which rests on the rubber ring. C. I. KELLY ANGLOAMERICAN OIL Co., LTD. PURFLBET,ESSEX, ENGLAND October 22, 1927
Formation of Petroleum Editor of Industrial and Engineering Chemistry: Apropos of the instructive r h m 6 by D. H. Killeffer, “A Year’s Progress in Chemistry,” in the October, 1927, number of Industrial and Enginetring Chemistry, in which he states that Fischer and Tropsch have advanced a theory that petroleum is formed by reaction similar to that involved in their preparation, a t low pressures, of high-melting, high-molecular weight hydrocarbons comparable to those present in paraffin waxes melting as high as 120” C., and that their said theory is the only one so far advanced by which it can be supposed that petroleum is still being formed in nature; it may be interesting to suggest that Mendelejeff advanced the theory that water acting on carbides (perhaps iron carbide) in the deep layers of the earth’s crust was responsible for the formation of petroleum. Sabatier and Senderens went much farther and actually created appreciable amounts of oil corresponding exactly with Pennsylvania crude in gravity, color effects, odor, and all physical and chemical properties tested, a t atmospheric pressure (if I remember ariehti bv simolv bringing acetvlene and hvdroeen toeether in
Corrections I n our article entitled “Polarized Platinum Electrode in Neutralization Reactions,” Ind. Eng. Chem., 19, 749 (1927), in the second sentence under Apparatus and Procedure the polarizing current should be 0.43 ampere X 10-6 instead of 2.3 X 10-6 amperes. -4.H. WRIGHTAXD F. H. GIBSON In “Use of Quinhydrone Electrode for Following Changes of p H in Swiss Cheese,” Ind. Eng. Chem., 19, 1272 (1927), the gages for the gold and platinum wire given on page 1272 should be interchanged. PAULD. WATSON
New Books Index to Proceedings, Volumes 21-25 (1921-1925). 224 pp. American Society for Testing Materials, Philadelphia. Price, $2.50. Schiess- und Sprengstoffe. Band XVI. Technische Fortschrittsberichte. PH. NAOUM. 212 pp. Theodor Steinkopff, Dresden. Price, 14 marks. Signidcance of the Elasticity and Thermal Expansion of Fireclays with Reference to the Spalling of the Fired Product. R. F. GELLER.Technologic Paper 4. 14 pp. Price, 50 cents. Kilns and Fuels for Firing Refractories. W. E. RICE. Bulletin 15. 8 pp. Notes on the Design of Fire Clay Shapes. E. H. VAN SCHOICK. Bullelin 16. 4 pp. American Refractories Institute, Pittsburgh, Pa.
