1. Certain metals by reason of their chemistry, electric reactions, solubility and other physical properties are less tolerated by human tissues than are others.
2. No demonstrable inhibitive effect was shown upon the colonies of staphylococcus aureus and bacillus pyocyaneus on blood agar and plain agar media.
3. It has been demonstrated that certain metals such as tin, gold, platinum, and silver cause less reaction in the body tissues than others and therefore, under such circumstances, organisms carried by the blood stream would be less prone to infect adjacent areas than where metals causing irritation were used.