Carbon material such as graphite and activated charcoal, but not diamond, causes the promotion of growth of certain bacteria under ordinarily non-permissive stress conditions over a distance of several centimeters. Bacillus carboniphilus under the stress of a high KCI concentration and high temperature responded to this remote effect of carbon material with enhanced growth, and thermophile bacterium Bacillus stearothermophilus responded similarly yet moderately under the stress of low

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... e. The remote effect of carbon was caused by its activation with external energy, probably of electromagnetic nature, as this effect was markedly decreased by sheltering the experimental system with an iron or aluminum barrier. Carbon material probably transforms the external oscillatory pulses or radiation into a signal exerting, far-reaching, growth-promoting effect upon cells. The most plausible candidate of signals emitted from carbon was considered to be (ultra)sonic.