The Microscope - Volume 69, Second Quarter 2022
On the cover:
The central stop dispersion staining (CSDS) colors of chrysotile (NIST SRM 1866) in 1.550 HD-L refractive index liquid from DRIMMC at 23 °C, α = 1.549; γ = 1.556. See The Dispersion Staining Technique and Its Application to Measuring Refractive Indices of Non-opaque Materials, with Emphasis on Asbestos Analysis, page 51. (Photomicrograph courtesy of Shu-Chun Su)
Editorial | Inter/Micro is Back
Gary J. Laughlin
The Microscope 69:2, p ii, 2022
Excerpt: After canceling the Inter/Micro microscopy conference in 2020 and 2021 due to the pandemic, McCrone Research Institute is excited to host it again on Sept. 20 – 23 in Chicago, marking the 72nd anniversary of this international, in-person meeting.
The Dispersion Staining Technique and Its Application to Measuring Refractive Indices of Non-opaque Materials, with Emphasis on Asbestos Analysis
Shu-Chun Su, Ph.D.
The Microscope 69:2, pp 51 – 69, 2022
Abstract: Refractive index (RI) is the most important optical property of non-opaque materials. It is the leading diagnostic optical property of non-opaque materials, especially asbestos minerals. Dispersion staining (DS) has been proven to be the most effective technique with desirable accuracy for the measurement of asbestos minerals’ RI using the immersion method by polarized light microscopy (PLM). This paper presents a practical procedure for this measurement. To facilitate the analysis, two comprehensive suites of pre-calculated look-up tables for the conversion of the observed matching wavelength to RI were constructed for the two major types of RI liquids: Cargille Laboratories (Cargille) and Delaware Research Institute of Microscopy and Material Characterization LLC (DRIMMC), respectively, covering the range of RI liquids suitable for analyzing the six regulated asbestos minerals. RI liquid calibration in the absence of an Abbe refractometer is discussed. An alternative solution using Cargille optical glass standards is proposed, and two comprehensive suites of pre-calculated look-up tables for both Cargille and DRIMMC liquids are included, covering the range of RI liquids routinely used in the analysis of the six regulated asbestos minerals.
Download/view conversion tables (PDF):
Cargille Asbestos RI Measurement
DRIMMC Asbestos RI Measurement
Cargille RI Liquid Calibration
DRIMMC RI Liquid Calibration
CORRECTIONS: On page 59 of the published article, the Figure 7 illustration is an error and does not depict the “light path of the phase contrast microscope,” as stated in the caption. It is the light path of a darkfield microscope.
On page 63 of the published article, the temperature ranges are incorrect for Table 5. λ m and t to RI Conversion for Chrysotile in Cargille 1.550 (E). The correct temperature ranges are 17° to 29° C.
Download/view the PDF of the corrected Table 5
Critical Focus | The Cell Knows Who You Are
Brian J. Ford
The Microscope 69:2, p 70 – 83, 2022
Excerpt: Can we alter our sexuality with a knife and a few chemicals? A sectioned rat fetus reminds us how we all truly began: as multicellular organisms with their own hard-wired identity.
My favorite slide is a rat fetus I sectioned as a student. This is such a revealing preparation. Everyone likes it — and everybody (absolutely everybody) points out its penis. The penis indicates at once that this is a male fetus — or at least, it did until recently. Now, transsexuals who are women but are desperate to be men, can have one created by a surgeon. Or can they? Of course not. You can no more fashion a fully functioning penis out of tissue than you can make a line-caught cod out of a tall tub of taramasalata. Men invading a women’s racetrack or the privacy of their changing room are ineradicably men, no matter what tablets they take. It is the microscope which proves the point.
New Microcrystal Tests for Controlled Drugs, Diverted Pharmaceuticals, and Bath Salts (Synthetic Cathinones): Alpha-PVP
Sebastian B. Sparenga M.S.; Gary J. Laughlin, Ph.D.; Meggan B. King, B.Sc.; and Dean Golemis, B.A.
The Microscope 69:2, pp 84 – 91, 2022
Abstract: The Microscope is publishing selected monographs from McCrone Research Institute’s recently completed research, New Microcrystal Tests for Controlled Drugs, Diverted Pharmaceuticals, and Bath Salts (Synthetic Cathinones), which contains newly developed microcrystal tests and reagents with 9 additional drugs: alprazolam, butylone, mephedrone, methylone, MDPV, 4-MEC, alpha-PVP, tramadol, and zolpidem. This issue includes the monographs for the following drugs/reagents:
• Alpha-PVP/palladium chloride with hydrochloric acid and phosphoric acid
• Alpha-PVP/potassium ferrocyanide with hydrochloric acid
Microscope Past: 50 Years Ago | Some Observations Made with a Spectrum Projected into the Plane of the Object
The Microscope 69:2, pp 92 – 95, 2022
Originally published in The Microscope, Volume 20, Fourth Quarter, pp 319 – 326, 1972.
Abstract: Refractive index determinations by immersion methods may sometimes be facilitated by finding the wavelength within the spectrum where the Becke line disappears. This procedure was tried using fibers illuminated by a spectrum projected into the plane of the object.
Afterimage | 20th Century Forgery
Oppenheimer Goldberg — McCrone Research Institute, Chicago
The Microscope 69:2, p 96, 2022
Particles of Vinland Map anatase, by transmission electron microscopy (TEM), 25,000x. Note rounded to well-formed, angular, single, submicrometer crystals, which could only have been commercially manufactured after 1920. The Vinland Map was purported to be a 15th century creation, but it was declared a fake in 1973 by Walter and Lucy McCrone, who analyzed it with PLM and electron microscopy. Learn more
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