Abstract: Disclosed is a mounting structure incorporating an exposed micro-sample of a particulate dry solid of interest, including a discrete adhesive covered circular plastic disc having a uniform exposed mono-layer of the particulate solid adhered to the surface of the adhesive and a handle mounted to the opposite side of the disc to facilitate exposure and retrieval of the micro-sample to and from various reactive media. The disc, adhesive and handle portion mounting the disc are of transparent generally inert, polypropylene plastic and acrylic adhesive materials, which are chemically dissimiliar to and non-reactive with the particulate solid.

Abstract: Disclosed is a conventional safety razor having a sounding board disposed immediately behind and approximately coextensive and even with the razor head, the sounding board being in the form of a thin plastic plate extending upwardly from the razor handle, with the plate serving as both a means for scraping hair stubble on human skin, as well as a means for audibly amplifying vibrations induced thereby. This alerts the user to the continued presence of objectionable hair stubble so that the shaving process is repeated with or without a change of safety razors or razor blades as required. Alternatively, a miniature solid-state microphone may be mounted on the safety razor for sensing the vibrations and driving an audio speaker through an amplifier/filter network.