In formaldehyde we have a most valuable agent with which to control and destroy infectious germs, but the properties of this gas and its effects on living cells must be understood to apply it within its limitations. It is a well-known fact that, even in small quantities, it has a peculiar effect on fibrin, hardening and otherwise changing its physical properties. A small amount added to egg albumin or blood serum so changes them that they will not coagulate on heating. To the power of this gas to penetrate the cell wall of bacteria and alter its properties are we indebted for its germicidal qualities.
The destructive power of many pathogenic germs depends on their ability to multiply rapidly and overwhelm their host before resisting forces can be brought to bear. But it is a universal law of Nature that things of rapid growth are also of delicate structure, and
JAQUES WK. FORMALDEHYDE DISINFECTION.. JAMA. 1900;XXXIV(2):78–80. doi:10.1001/jama.1900.24610020014002e