Roberts, L. B.

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Journal of the Arkansas Academy of Science Volume 1 Article 24 1941 Some Useful Devices for the Chemical Laboratory L. B. Roberts University of Arkansas at Monticello Follow this and additional works at: https://scholarworks.uark.edu/jaas  Part of the Other Chemistry Commons Recommended Citation Roberts, L. B. (1941) "Some Useful Devices for the Chemical Laboratory," Journal of the Arkansas Academy of Science: Vol. 1 , Article 24. Available at: https://scholarworks.uark.edu/jaas/vol1/iss1/24 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu. 75SOME USEFUL DEVICES FOR THE CHEMICAL LABORATORY 1L. B. Roberts, Arkansas Agricultural and MechanicalCollege, MonticelloThe purpose of this paper is to pass on to others the ideasfor several devices that have proved their value under regularlaboratory use. Although no claim is made for the strictoriginality of all the basic ideas underlying these devices,their adaptation and development have been at least more or lessindependent.A gas evolution tube for use with test paper may be madefrom 6-mm glass tubing. One end of a two-inch length of tubingis sealed and the other flared with a long taper. Another two-inchlength of tubing is drawn to a small jet with taper to matchthe flare of the first tube, and its other end is given a shortflare. The two pieces are then ground to a joint with carborundumpowder, the finishing being done with powder of about 400 meshfineness.A gas evolution tube for test solutions is made in a similarmanner. The first tube is the same but the second is made intwo parts and sealed together. The part carrying the taper forthe ground joint is drawn out, close to the taper, to a long thinjet which is bent back upon itself. This bent jet is sealed intothe other piece, forming a reservoir for a liquid and a bubblingtube for passing a gas through the liquid.A useful micro-beaker is made from a 6-inch glass or pyrextest tube by flattening the bottom while red hot, against asuitable surface, cutting to proper length with a hot wire,turning a lip, and tooling a spout. An asbestos shingle makes asatisfactory flattening surface, a dry cell carbon sharpened toa pyramid point serves well for turning the lip, and the tang ofa small file tools the spout nicely.An excellent separator for recovering small amounts of oilfrom large volumes of water has been made by sealing a small tubeto an opening blown in the bottom of a test tube, bending to forma U-tube of unequal arms, bending again opposite the middle ofthe test tube to a slight downward slope when the test tube isvertical, and cutting just beyond the last bend.For re-distillation of small yields from organic preparationsa self-contained distillation apparatus Is made from a 10-mldistilling flask and a few pieces of tubing. A 12-inch extensionis sealed to the delivery tube of the flask and fitted with a con-denser jacket made from 10-mm tubing, after which the end is bentdown to form an adapter. If the water outlet of the condenserjacket is made extra long and bent downward, kinks in the rubberhose connected to it are discouraged.For preventing the escape of fumes from Kjeldahl digestionsinto a laboratory not equipped with hoods an 8- inch test tube 3/4full of water supported by its lip in the neck of the Kjeldahlflask has been found very satisfactory. Though possibly not sogood as the porous capsules made for the purpose, it is also notso expensive. Another means of disposing of fumes is the ordinaryaspirator. For much use with corrosive fumes a glass aspiratoris preferable to one of brass, and a serviceable one may beassembled from a T-tube, a glass jet, and a rubber stopper.Condensed from a paper presented at the 1940 meeting.75Journal of the Arkansas Academy of Science, Vol. 1 [1941], Art. 24Published by Arkansas Academy of Science, 194176Empty quart motor oil cans have been bound useful for severalpurposes. They serve as water baths, ice containers, individualtrash cans, burner chimneys (with both ends out), and even aspneumatic troughs. Cans of other sizes also find ready uses inthe laboratory.In this connection it seems well to mention the use ofordinary carpet tacks for cleaning deposits of carbon from insidedistilling flasks, of a copper wool scouring pad for more access-ible deposits, and of pipe-stem cleaners for small tubes. Oldrazor blades also find uses in removing labels, paint, or othermatter from outer surfaces of glass or porcelain.One other adaptation seems worthy of being passed on.Through the cooperation of the supply house it was found possibleto replace the tapered shields of an inexpensive hand centrifugewith round-bottomed brass shields that take ordinary 5-inch testtubes. (The rubber cushions were replaced by thinner ones.) Thusa separation by centrifuge may be made directly in the test tube.Having described several simple devices that can be made fromcommon materials with moderate skill and little cost, the authorhopes that other workers may find them useful.PETRIFIED WOOD COMPOUND OF OXIDES OF IRON1L. B. Roberts, Arkansas Agricultural and MechanicalCollege, Mont icelloSpecimens of petrified wood found in the Tertiary EoceneW11cox sand exposed in bluffs over Red River at Shreveport proveto be composed of oxides of Iron (assumed to be hematite andlimonite) with no appreciable quantity of organic matter or ofsilica. Ordinary silicified wood (with occasional specimenspartly lignitized) is common in the region, as are small bodies ofhematite. Stem and leaf imprints, usually fragmentary, in Iron-bearing stones are fairly common. Irregular beds of ligniteunderlie much of the region.Abstract of a paper presented at the 1939 meeting and published incondensed form in the Journal of Geology, Vol. XLVIII,No. 2,February—March, 1940, pp. 212, 213.76Journal of the Arkansas Academy of Science, Vol. 1 [1941], Art. 24https://scholarworks.uark.edu/jaas/vol1/iss1/24

Some Useful Devices for the Chemical Laboratory

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Journal of the Arkansas Academy of ScienceVolume 1 Article 241941Some Useful Devices for the Chemical LaboratoryL. B. RobertsUniversity of Arkansas at MonticelloFollow this and additional works at: http://scholarworks.uark.edu/jaasPart of the Other Chemistry CommonsThis article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able toread, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking priorpermission from the publisher or the author.This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academyof Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu, ccmiddle@uark.edu.Recommended CitationRoberts, L. B. (1941) "Some Useful Devices for the Chemical Laboratory," Journal of the Arkansas Academy of Science: Vol. 1 , Article24.Available at: http://scholarworks.uark.edu/jaas/vol1/iss1/2475SOME USEFUL DEVICES FOR THE CHEMICAL LABORATORY 1L. B. Roberts, Arkansas Agricultural and MechanicalCollege, MonticelloThe purpose of this paper is to pass on to others the ideasfor several devices that have proved their value under regularlaboratory use. Although no claim is made for the strictoriginality of all the basic ideas underlying these devices,their adaptation and development have been at least more or lessindependent.A gas evolution tube for use with test paper may be madefrom 6-mm glass tubing. One end of a two-inch length of tubingis sealed and the other flared with a long taper. Another two-inchlength of tubing is drawn to a small jet with taper to matchthe flare of the first tube, and its other end is given a shortflare. The two pieces are then ground to a joint with carborundumpowder, the finishing being done with powder of about 400 meshfineness.A gas evolution tube for test solutions is made in a similarmanner. The first tube is the same but the second is made intwo parts and sealed together. The part carrying the taper forthe ground joint is drawn out, close to the taper, to a long thinjet which is bent back upon itself. This bent jet is sealed intothe other piece, forming a reservoir for a liquid and a bubblingtube for passing a gas through the liquid.A useful micro-beaker is made from a 6-inch glass or pyrextest tube by flattening the bottom while red hot, against asuitable surface, cutting to proper length with a hot wire,turning a lip, and tooling a spout. An asbestos shingle makes asatisfactory flattening surface, a dry cell carbon sharpened toa pyramid point serves well for turning the lip, and the tang ofa small file tools the spout nicely.An excellent separator for recovering small amounts of oilfrom large volumes of water has been made by sealing a small tubeto an opening blown in the bottom of a test tube, bending to forma U-tube of unequal arms, bending again opposite the middle ofthe test tube to a slight downward slope when the test tube isvertical, and cutting just beyond the last bend.For re-distillation of small yields from organic preparationsa self-contained distillation apparatus Is made from a 10-mldistilling flask and a few pieces of tubing. A 12-inch extensionis sealed to the delivery tube of the flask and fitted with a con-denser jacket made from 10-mm tubing, after which the end is bentdown to form an adapter. If the water outlet of the condenserjacket is made extra long and bent downward, kinks in the rubberhose connected to it are discouraged.For preventing the escape of fumes from Kjeldahl digestionsinto a laboratory not equipped with hoods an 8- inch test tube 3/4full of water supported by its lip in the neck of the Kjeldahlflask has been found very satisfactory. Though possibly not sogood as the porous capsules made for the purpose, it is also notso expensive. Another means of disposing of fumes is the ordinaryaspirator. For much use with corrosive fumes a glass aspiratoris preferable to one of brass, and a serviceable one may beassembled from a T-tube, a glass jet, and a rubber stopper.Condensed from a paper presented at the 1940 meeting.75Journal of the Arkansas Academy of Science, Vol. 1 [1941], Art. 24Published by Arkansas Academy of Science, 194176Empty quart motor oil cans have been bound useful for severalpurposes. They serve as water baths, ice containers, individualtrash cans, burner chimneys (with both ends out), and even aspneumatic troughs. Cans of other sizes also find ready uses inthe laboratory.In this connection it seems well to mention the use ofordinary carpet tacks for cleaning deposits of carbon from insidedistilling flasks, of a copper wool scouring pad for more access-ible deposits, and of pipe-stem cleaners for small tubes. Oldrazor blades also find uses in removing labels, paint, or othermatter from outer surfaces of glass or porcelain.One other adaptation seems worthy of being passed on.Through the cooperation of the supply house it was found possibleto replace the tapered shields of an inexpensive hand centrifugewith round-bottomed brass shields that take ordinary 5-inch testtubes. (The rubber cushions were replaced by thinner ones.) Thusa separation by centrifuge may be made directly in the test tube.Having described several simple devices that can be made fromcommon materials with moderate skill and little cost, the authorhopes that other workers may find them useful.PETRIFIED WOOD COMPOUND OF OXIDES OF IRON1L. B. Roberts, Arkansas Agricultural and MechanicalCollege, Mont icelloSpecimens of petrified wood found in the Tertiary EoceneW11cox sand exposed in bluffs over Red River at Shreveport proveto be composed of oxides of Iron (assumed to be hematite andlimonite) with no appreciable quantity of organic matter or ofsilica. Ordinary silicified wood (with occasional specimenspartly lignitized) is common in the region, as are small bodies ofhematite. Stem and leaf imprints, usually fragmentary, in Iron-bearing stones are fairly common. Irregular beds of ligniteunderlie much of the region.Abstract of a paper presented at the 1939 meeting and published incondensed form in the Journal of Geology, Vol. XLVIII,No. 2,February—March, 1940, pp. 212, 213.76Journal of the Arkansas Academy of Science, Vol. 1 [1941], Art. 24http://scholarworks.uark.edu/jaas/vol1/iss1/24

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Some Useful Devices for the Chemical Laboratory

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