Soft touch Subject

Hand The softness of fabric as determined by a touch, subject to the persons judgment. 

The end of the capillary tube is heated until the glass is soft, then before it has time to cool it is touched on to the surface of a thin bubble of glass and a slight suction applied. This forms the window into a concave shape and draws it slightly down into the capillary, whose ends then protect it from damage. The bubble of thin glass should be thin enough to show interference colours. These windows will stand a vacuum provided atmospheric pressure is on the concave side of the window. If they are subjected to a pressure difference in the other direction, failure occurs due to the reversal of curvature. 

Visible zones can directly be subjected to MS. Using plates with fluorescence indicator, UV-active zones of interest can be marked under the respective UV lamp by a soft pencil (carbon does not interfere with analyte signals). Do not touch the layer material by doing so and avoid recontamination. Native fluorescent zones can also be marked under the respective UV lamp. 

Talc is a naturally occurring hydrous magnesium silicate which is pulverized and subjected to flotation processes to remove mineral impiuities. The talc is then finely powdered and treated with dilute hydrochloric acid, washed with water and dried. It is very fine, white to grayish white, impalpable, and odorless. Talc is a crystalline powder, unctuous, and adheres readily to the skin. It is soft to the touch and free from grittiness. To be classified as Talc USP, the following specifications must be met ... 

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