A more familiar common use is in silver-coloured modern circulation coins. A typical mix is 75% copper, 25% nickel, and a trace amount of manganese. In the past, true silver coins were debased with cupronickel. Despite high copper content, cupronickel is dark bronze in colour when in storage, but is a light copper colour when polished. Thermocouples and resistors whose resistance is stable across changes in temperature contain the 55% copper-45% nickel alloy constantan.
For the past 3 months, I've been taking several popular nootropics in relatively recommended dosages. The results have been generally positive (mental stamina, desire to learn, impressive thoughts at times), however, I am experiencing the following unwelcome side-effects. -Rash and skin irritation.
Side effects of mydriatics include: 1  Whitening of the eyelids and skin around the eyes. 2  This is completely harmless and will resolve spontaneously. 3  It is due to the constriction of small skin blood vessels. 4  Atropine can cause redness/flushing of the face, a warm sensation of the skin to touch, irritability or sweating.