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The Microscope – Volume 61, Second Quarter 2013

IN THIS ISSUE
On the cover
A SEM image of severed yarn shows polyester ends (circled)that have globular ends characteristic of a high-speed, highenergy fracture mechanism. Arrows point to broken cotton fibers, which do not have globular ends. See Plumbum Microraptus: Definitive Microscopic Indicators of a Bullet Hole in a Synthetic Fabric, page 51. (Courtesy of Christopher S. Palenik)
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Editorial | Light Microscopy and the Study of Things
Gary J. LaughlinThe Microscope 61:2, p. ii, 2013https://doi.org/10.59082/HRNO6470 Excerpt: Do scientists or students of natural or physical science really need to learn how to use the light microscope? That is a question I often address, or in this case, when it’s time to write my editorial for this journal, whose primary audience consists of seasoned microscopists or novices who are still learning new ways to use the microscope to solve their scientific problems.
Plumbum Microraptus: Definitive Microscopic Indicators of a Bullet Hole in a Synthetic Fabric
Christopher S. Palenik, Skip Palenik and Peter DiaczukThe Microscope 61:2, pp. 51–60, 2013https://doi.org/10.59082/OQKX5823 Abstract: A central question in a criminal forensic investigation involved a hole (later termed a “defect”) observed in a garment and whether it was produced by a bullet or some other means. The individual wearing the item was known to have fired or been in the vicinity of a firearm that was discharged, rendering the presence or absence of gunshot residue on the garment irrelevant. The micromorphology and elemental composition of the severed fiber ends in a series of exemplar bullet holes were characterized to identify specific physical indicators of the bullet-garment interaction on a microscopic scale. This study confirms prior research indicating that fiber failure, due to the highenergy transfer from a bullet to a synthetic fabric, is consistent with a high-speed tensile fracture mechanism, which results in characteristic fiber-end micromorphology due to partial melting. In addition, scanning electron microscopy (SEM) imaging and elemental analyses by energy-dispersive X-ray spectroscopy (EDS) provide direct evidence of the capture of detectable microscopic lead particles both on and within the melted fiber ends, a process termed here as plumbum microraptus (microscopic lead capture). These lead particles are observed primarily as planar abrasion fragments but also as spherical particles, the latter of which further illustrates the high-energy transfer. Through the study of individual broken fibers from within a suspected bullet hole, these characteristic indicators provide a minimally invasive and direct means to definitively associate or (equally important) dissociate a fabric defect with a bullet perforation.
Critical Focus | Shining the Spotlight on Movie Microbes
Brian J. Ford The Microscope 62:1, pp. 63–73, 2013 https://doi.org/10.59082/JRWJ9483 Abstract: “Marilyn Monroe was a confused, sweet angel,” said our visitor, as the sun sparkled on his crystal glass of orange juice. “And Cary — did you know he was born in Britain? Cary Grant was so muddled in his mind. He and I became such good friends. Archibald Leach, he was called originally. Poor chap ran away to become a performer when his mother was locked up in a mental institution in Bristol and nobody told him about it. It’s strange what makes people into movie stars.” My dear friend Charles Bennett had been born in 1899, and stayed with us in Cambridgeshire when he was 94. He was Alfred Hitchcock’s first scriptwriter and lived next to Mel Tormé in Beverly Hills. I remember Charles’s desk at his home cluttered with portrait photos and résumés for would-be actors, each eager for fame. “What makes people into movie stars?” mused Charles. “Nobody knows. That would make such an interesting piece of scientific research.”
Calculated Nominal Ranges of Refractive Indices for the Amphiboles Found in the Rainy Creek Igneous Complex
Matthew S. Sanchez and Mickey E. Gunter The Microscope 61:2, pp. 75–84, 2013 https://doi.org/10.59082/LFFD1588 Abstract: The amphiboles occurring in the Rainy Creek Igneous Complex (RCC) near Libby, Montana, range in composition such that the following amphibole species have been identified: tremolite, winchite, richterite, magnesioriebeckite and magnesioarfvedsonite. The composition, optical and crystallographic values of only winchite and richterite have been determined. In an attempt to characterize the nominal (i.e. mean) refractive index for tremolite, magnesioriebeckite and magnesioarfvedsonite species, derivations of Gladstone-Dale constants specific to the RCC were attempted. It was not possible to obtain specific Gladstone-Dale constants using these data for the RCC amphiboles. Therefore, the Gladstone-Dale constants derived by Jaffe (1) for the alkali amphiboles were applied to the published electron probe microanalysis (EPMA) data from Meeker et al. (2) specific to tremolite and magnesioriebeckite, as well as the data from Sanchez et al. (3) for magnesioarfvedsonite. (Note: Dyar and Gunter [4], and references therein provide more information on amphibole nomenclature and correlations of refractive indices to mineral structures.) The range of nominal refractive indices for the tremolite, magnesioriebeckite and magnesioarfvedsonite are calculated as n=1.610 to 1.629, n=1.646 to 1.665 and n=1.641 to 1.652, respectively. The nominal range of refractive indices for the amphiboles occurring within the RCC is much smaller than the ranges for amphiboles under current International Mineralogical Association nomenclature for magnesioarfvedsonite and magnesioriebeckite and their solid solutions. Therefore, caution is required when using the optical properties.
“Microscope” — A Lost Poem by Louis Ginsberg
Randy Wayne The Microscope 62:1, pp. 85–87, 2013 https://doi.org/10.59082/KEXG5988 Abstract: “Microscope” — A Lost Poem by Louis Ginsberg Randy Wayne Laboratory of Natural Philosophy, Department of Plant Biology, Cornell University Microscopists know that the world is both big and small. Every year I take my light microscopy class to the Rare & Manuscript Collections at Kroch Library of Cornell University. David Corson, the curator of the History of Science Collections, shares his knowledge and love of books and science with my students. He makes it possible for my students to travel through time when he shows them Robert Hooke’s Micrographia (published in 1665, Christian Huygens’ Traiteì de la lumiere (1690), Isaac Newton’s Opticks, or, A treatise of the reflections, inflections and colours of light (1704), Henry Baker’s The microscope made easy (1741), George Adam’s Micrographia illustrata (1746), his son George’s Essays on the microscope (1787), Thomas Young’s A course of lectures on natural philosophy and the mechanical arts (1807) and many other books on light and microscopy.
The Microscope Past: 20 Years Ago | Diatoms
Robert B. McLaughlin The Microscope 61:2, pp. 89–93, 2013Originally published in The Microscope, Vol. 41, No. 1, 1993 Excerpt: Diatom Microscopy Cyclotella jonesii McLaughlin, a new diatom from Chiloquin, Oregon. As this new diatom has just recently been validly published (1), notification of it in this journal may seem redundant. However, this particular diatom has special meaning to me, and to the editors and readership of The Microscope. The specific epithet has been chosen to recognize Dr. Francis T. Jones of Berkeley, California. Dr. Jones has, over the years, contributed many fine technical papers to this publication, and is well known for his expertise in optical crystallography.
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