Microscopic preparations, defects

As a result of checking a series of dyes, it has been found that the dye Sudan III—IV (mixture) is sorbed defectively by KL-3 preparations. The intensity of dyeing to a reddish-orange color is so strong that it is possible to determine particles of the adhesive in the preparation up to a size of 3 pm (Ref.15>, p. 69). Microscopic investigations of the experimental material have been performed in glueing wound surfaces of different animal organs by the KL-3 adhesive. The results... 

We studied samples of La lecithin with 16-29% water at room temperature. The samples were prepared between two microscope glass slides that were first treated with a sulfochromic solution, then carefully rinsed with distilled water and dried. They were observed by transmission polarizing microscopy. Just after deposition between the slides, the samples present a highly disordered texture which strongly diffuses light. After compression (squeezing) and/or shearing parallel to the plates, one obtains an overall homeotropic orientation that is perturbed by defects. The thickness of the samples is in the order of 20/. ... 

Other types of extrinsic deviation are found in the special properties imparted to small particles by the manner of their preparation. For example, production of small particles by grinding in a mill alters the heat of adsorption of gases by the particles. In general, the method of particle production may introduce defects or microscopic impurities that differ from what is found in the parent material. Often extrinsic and intrinsic deviations occur in the same physical property, as in the example of supercooling of sodium chloride cited above. This fact makes the study of intrinsic deviations very difficult. 

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