This object is a 300 mL Kjeldahl flask made by the Rheinische Glashutten-Actien-Gesellschaft.
In 1883 Danish chemist Johan Kjeldahl (1849–1900) of the Carlsberg Laboratory published the Kjeldahl method. It was the first accurate, simple, and speedy way to determine nitrogen content in organic matter.
Kjeldahl’s employer, Carlsberg Laboratory, had been originally established as a place for scientific research to perfect the process of beer making. Later, the laboratory took on a broader mission to contribute to pure research. The need for the Kjeldahl method grew from his analysis of the protein content of grains for beers at different stages—from germination to fermentation as beer wort. Analyses of nitrogen content can be used to quantify the amount of protein in a sample, and protein content of grains influences the volume of beer they produce.
The Kjeldahl method proved to have wide-ranging applications and was quickly adopted by scientists from a variety of fields. In the mid-2010s, the method (with minor modifications) was still in use for purposes ranging from analysis of protein in foods to nitrogen content in soil samples. To “Kjeldahl” a sample has become a verb in chemical parlance, considered by some the greatest honor bestowed by the chemical community.
Along with his method, Kjeldahl’s name also became attached to a piece of laboratory equipment he developed in 1888. The long-necked, round-bottomed flask was ideal for avoiding splashback when heating solutions. Splashback was a threat during the first step of the Kjeldahl method—which requires heating the sample in concentrated sulfuric acid.
Rheinische Glashutten-Actien-Gesellschaft was a German glassworks located in Ehrenfeld, Cologne, from 1872 through 1937. The company introduced a chemically resistant glass, similar to Jena glass, for laboratory use as early as 1909.
This object is part of a collection donated by Barbara Keppel, wife of C. Robert Keppel. Robert Keppel taught at the University of Nebraska-Omaha after receiving his B.S. in Chemistry from the University of California, Berkeley, and his Ph.D. in organic chemistry from M.I.T. The glassware in the Keppel collection covers the 19th and early 20th centuries.
Sources:
Burns, D. Thorburn, and W. I. Stephen. “Kjeldahl Centenary Meeting.” Analytical Proceedings 21, no. 6 (1984): 210–20. doi:10.1039/AP9842100210.
Buse, Stephan. “Eine Wieder Entdeckte Preisliste Der Rheinischen Glashütten AG Ehrenfeld Bei Köln von 1877 - Hartglas Nach Dem Verfahren A. de La Bastie.” Pressglas-Korrespondenz 4, September (2007).
Cauwood, J.D., and W.E.S. Turner. “The Attack of Chemical Reagents on Glass Surfaces, and a Comparison of Different Types of Chemical Glassware.” Journal of the Society of Glass Technology 1 (1917): 153–62.
National Museum of American History Accession File #1985.0311
Sáez-Plaza, Purificación, Tadeusz Michałowski, María José Navas, Agustín García Asuero, and Sławomir Wybraniec. “An Overview of the Kjeldahl Method of Nitrogen Determination. Part I. Early History, Chemistry of the Procedure, and Titrimetric Finish.” Critical Reviews in Analytical Chemistry 43, no. 4 (2013): 178–223. doi:10.1080/10408347.2012.751786.
“University of Nebraska Omaha.” 2015. Accessed May 4. http://www.unomaha.edu/college-of-arts-and-sciences/chemistry/student-opportunities/scholarships.php.
Compound monocular microscope with double nosepiece, mechanical stage, trunnion, Abbe condenser, Lister limb with sub-stage mirror, and tripod foot. It has a diagonal rackwork for coarse adjustment, and long lever for fine focus. The stand is brass finished in black enamel. The inscription reads “W. WATSON & SONS / 313 HIGH HOLBORN / LONDON.” The serial number is 5211.
This form, termed the Edinburgh Student’s Microscope, was introduced in 1889 and remained in production for decades. It incorporated suggestions made by Alexander Edington, a lecturer on bacteriology at Edinburgh University. The several versions were designated A through H. This example is an H.
Ref: T.N. Clarke, A.D. Morrison-Low, and A.D.C. Simpson, Brass & Glass (Edinburgh, 1989), p. 87.
This object is a Graham coil condenser made from Pyrex glass. A Graham condenser is used to cool and condense a gas back to a liquid, often as part of the process of chemical distillation. The piece consists of a coiled glass tube through which the gas travels. The coil is surrounded by a jacket of water that helps to cool the gas.
Pyrex has its origins in the early 1910s, when American glass company Corning Glass Works began looking for new products to feature its borosilicate glass, Nonex. At the suggestion of Bessie Littleton, a Corning scientist’s wife, the company began investigating Nonex for bakeware. After removing lead from Nonex to make the glass safe for cooking, they named the new formula “Pyrex”—“Py” for the pie plate, the first Pyrex product. In 1916 Pyrex found another market in the laboratory. It quickly became a favorite brand in the scientific community for its strength against chemicals, thermal shock, and mechanical stress.
Sources:
Dyer, Davis. The Generations of Corning: The Life and Times of a Global Corporation. Oxford, New York: Oxford University Press, 2001.
Jensen, William B. “The Origin of Pyrex.” Journal of Chemical Education 83, no. 5 (2006): 692. doi:10.1021/ed083p692.
Kraissl, F. “A History of the Chemical Apparatus Industry.” Journal of Chemical Education 10, no. 9 (1933): 519. doi:10.1021/ed010p519.
Henry Draper (1837-1882) was a New York physician, and pioneer of astronomical photography and spectroscopy. This is his research notebook XI, and it runs from June 27, 1872 to April 24, 1876. Tipped into the notebook are numerous photographs of astronomical spectra, peeled off of the original glass backings.
Ref: George F. Barker, “Memoir of Henry Draper,” Biographical Memoirs of the National Academy of Sciences (1888), pp. 81-139.
Babcock test bottles, featuring a long, thin neck with graduations from 0-50 were designed to test the fat content in cream.
The late-19th-century interest in nutrition, unadulterated foods, and truth in labeling led to a demand for a simple test to determine milk quality. At the time, milk was sold by weight. This led some farmers to water down their product or skim cream from the top, punishing honest farmers and creating an unpredictable quality in milk for the public. The University of Wisconsin tasked Professor Stephen M. Babcock (1843–1931) with finding a solution to this problem, and in 1890 he announced the Babcock test.
Earlier tests could accurately determine milkfat levels but were too lengthy and expensive to be widely implemented. Babcock’s test delivered a simple, time- and cost-effective solution that dairymen quickly adopted. The test not only provided a reliable way to determine fair prices for milk based on quality, but it also became a useful tool for animal breeding. By keeping consistent records of each cow’s milkfat production, farmers could breed their herds for improved milk.
As the test’s popularity grew, so did the demand for cheap but accurate graduated test bottles, pipettes, and graduated cylinders to carry out the test. The test required a milk sample of a standard weight, to which the tester added precise amount of sulfuric acid. The acid dissolved all of the milk constituents except for the fat, which floated to the surface. After heating and several spins in a centrifuge, the fat became trapped in the neck of the bottle. The tester could determine the percentage by reading graduations between which the fat fell.
Sources:
Babcock, S.M. 1890. “A New Method for the Estimation of Fat in Milk, Especially Adapted to Creameries and Cheese Factories.” In Annual Report of the Agricultural Experiment Station of the University of Wisconsin for the Year... University of Wisconsin Agricultural Experiment Station.
In an effort to get a better fix on the distance between the Earth and the Sun, the United States sponsored eight parties to observe the 1874 transit of Venus across the face of the sun, and equipped each with apparatus made by Alvan Clark & Sons. This 5-inch aperture achromatic lens in a brass cell was probably the objective for one of the eight equatorial refractors. The inscription on the cell reads “857”. This was sent to Peking for the 1874 transit.
Ref: Simon Newcomb, ed., Observations of the Transit of Venus, December 8-9, 1874 (Washington, D.C., 1880), p. 16.
This is a 5-inch aperture objective lens. The “J.W. Fecker / Pittsburgh / 1939 / Apochromat 180o Focus / Correct in Cell” inscription refers to James Walter Fecker, the optical instrument maker in Pittsburgh who made this example for the U.S. Naval Observatory. An apochromat is a lens with minimal chromatic or spherical aberration. Ernst Abbe, Research Director of the Zeiss Optical Works in Jena, introduced the term in the 1880s, in reference to his microscope objectives made with the new Schott optical glass.
Made of soft plush fabric and stuffed with batting, this large arm puppet represents Thomas Edison, one of the three puppets created to appear in the Lemelson Center program "The Renaissance Man", a celebration of the 150th birthday of Lewis Latimer (1848-1928) an African American scientist, inventor, and engineer. In addition to Edison, the Lemelson Center commissioned the Brewery Troupe of Freeport, New York to create Lewis Latimer and Frederick Douglass to be part of this program.
The Brewery Troupe was founded in 1973 by Brad Brewer, an accomplished puppeteer who trained under Jim Henson and performed puppet shows on TV and stage. The Brewery Troupe's goal is to interpret African American literature, music, and humor through the art of the puppet theater.
University of Cambridge. Department of Physics. Cavendish Laboratory
ID Number
EM.N-08014
accession number
224580
Description
J.J. Thomson's positive ray apparatus, replica of Cavendish Lab apparatus. Object ID EM.N-08014; Overall length 62 cm x width 35 x height 44 cm.
Object is a replica of the original which resides at Cavendish Laboratory, Cambridge University, England. Wood base supports, at one end, a horizontal glass discharge tube attached to a chamber fitted between the poles of an electromagnet. The chamber contains a pair of plates for deflection of the beam of "positive rays" (ions) passing through from the discharge tube. The rays fall on a phosphorescent screen at the other end of the apparatus, where a photographic plate can also be positioned.
Basic Principle
Thomson's positive ray apparatus were analogous to his cathode-ray tubes (see objects EM.N-08013A and EM.N-08013B); in that they measured the ratio of charge to mass of "positive rays" instead of electrons (cathode rays).
Ions, created by an electric discharge in the glass bulb, are accelerated towards its mouth. This beam of "positive rays" is then deflected vertically by a magnetic field and horizontally by an electric field, forming a parabolic trace on a phosphorescent screen—all atoms or molecules of the same charge-to-mass ratio falling along one parabola. This object is a replica of the fourth such apparatus Thomson constructed. With it, the traces were recorded photographically for the first time. For a concise review of J.J. Thomson, the Cavendish Laboratory, and Thomson's cathode ray tube and positive ray apparatus, see J .J. Thomson - the Centenary of His Discovery of the Electron and his invention of Mass Spectrometry, Rapid Communications in Mass Spectrometry, Vol.11, 2-16 (1997).
In 1876, an English scientist named Francis Galton introduced a whistle for testing the upper limits of audible sound in different persons. One of Galton's discoveries was the loss of hearing in high frequencies as persons aged. The whistle was often used in later psychological experiments where the subject was asked to indicate the discernment of tones. The whistle's inability to emit a tone of constant pitch was it's main deficit, leading many researchers away from its use, especially as electronic equipment became available.
The “EDELMANN / MUNICH” inscription on this example is that of Max Thomas Edelmann, an instrument maker in Munich who improved the form in 1900. The serial number is 468.
Ref: “The Galton Whistle,” Science 12 (1900): 613.
Physikalisch-mechanischen Institut von Prof. Dr. M. Th. Edelmann & Sohn, Die Edelmannschen Grenzpfeifen (Galtonpfeifen) von D. M. Edelmann (Munich, 1921).
Galton, Francis, "Inquries into Human Faculty and Its Development: Whistles for Audibility of Shrill Notes (1883), in Dennis, W. Readings in the History of Psychology, Appleton-Century-Crofts, 1948: 277
Small compound monocular with square stage, sub-stage mirror, and unusual rack-and-pinion focus. This was owned by Richard Halsted Ward (1837-1917), a noted medical microscopist, or his son, Henry B. Ward, a pioneering parasitologist.
Hideyo Noguchi (1876-1928) was a Japanese bacteriologist who moved to the U.S. in 1900 to work with Simon Flexner at the University of Pennsylvania. A few years later, having gone with Dr. Flexner to the newly-established Rockefeller Institute for Medical Research in New York, Dr. Noguchi used this microscope to study of the causal agent of syphilis.
This is a compound monocular with coarse and fine focus, triple nosepiece, large circular stage covered with vulcanite, trunnion, Abbé illuminating apparatus, black horseshoe base, and wooden box with extra lenses. The “CARL ZEISS / JENA” logo, introduced in 1904, appears on the tube. The serial number is 51900.
Ref: Eimer & Amend, Microscopes and Microscopical Accessories (Jena, 1902), pp. 50-51.
This is a compound monocular with coarse and fine focus, trunnion, square stage, and support for sub-stage diaphragm and for mirror. The tube and trunnions are nickel; the arm and the curvaceous Y-shaped foot are Japanned cast iron; the stage is glass. The eyepiece is missing. The inscription on the tube reads “BAUSCH & LOMB OPTICAL CO. / ROCHESTER. N.Y.” The donor identified this as a Model F made around 1882.
Compound monocular with coarse and fine focus, tilting hinge, triple nosepiece, square stage, sub-stage mirror, horseshoe base, and an inscription that reads “THE ‘DAVON’ SUPER MICROSCOPE / PATENT No. 10670 - 14 / F. DAVIDSON & CO. / LONDON, W. / 65A.”
Davidson boasted that “This apparatus combines in standardized and instantly interchangeable form the functions of the microscope, telescope, camera and projecting lantern for laboratory, educational and industrial purposes.”
Ref: F. Davidson & Co., The Davon Micro-Telescope and Super Microscope (London, 1914).
P. J. Risdon, “Microscope and Telescope Too,” Popular Science Monthly (May 1921): 60-61.
The Excelsior Pocket and Dissecting Microscope is a simple and inexpensive instrument that fits into and pops out of a small wooden box. It was designed by John J. Bausch, produced by Bausch & Lomb, and widely distributed in the 1870s.
Ref: John J. Bausch, “Microscope,” U.S. Patent 151,746 (June 9, 1874).
The Excelsior Pocket and Dissecting Microscope: Intended for the Use of Students, Physicians, Naturalists, Miners, Families, etc., with Description of Its Construction and Method of Using It (Rochester, 187?).
James W. Queen & Co., Priced and Illustrated Catalogue of Optical Instruments (Philadelphia, 1874), pp. 40-41.
Bausch & Lomb, Price List of Microscopes (New York, 1877), n.p.
John Phin, Practical Hints on the Selection and Use of the Microscope (New York, 1877), pp. 27-30.
