Recently Dr. W. G. Hudson, an inspector in the Department of Health of New York, has invented a very ingenious "peppermint cartridge" for testing plumbing. The invention is, however, not yet manufactured, and is not on the market. CHAPTER X =Infection and Disinfection= Disinfection is the destruction of the infective power of infectious material; or, in other words, disinfection is the destruction of the agents of infection. An infectious material is one contaminated with germs of infection. The germs of infection are organic microoerganisms, vegetable and animal--protozoa and bacteria. The germs of infection once being lodged within the body cause certain reactions producing specific pathological changes and a variety of groups of symptoms which we know by the specific names of infectious diseases, e. g., typhoid, typhus, etc. Among the infectious diseases known to be due to specific germs are the following: typhoid, typhus, relapsing fevers, cholera, diphtheria, croup, tuberculosis, pneumonia, malaria, yellow fever, erysipelas, _septicaemia_, anthrax, _tetanus_, gonorrhea, etc.; and among the infectious diseases the germs of which have not as yet been discovered are the following: scarlet fever, measles, smallpox, syphilis, varicella, etc. The part of the body and the organs in which the germs first find their entrance, or which they specifically attack, vary with each disease; thus, the mucous membranes, skin, internal organs, secretions, and excretions are, severally, either portals of infection or the places where the infection shows itself the most. The agents carrying the germs of infection from one person to the other may be the infected persons themselves, or anything which has come in contact with their bodies and its secretions and excretions; thus, the air, room, furniture, vessels, clothing, food and drink, also insects and vermin, may all be carriers of infection. =Sterilization= is the absolute destruction of _all_ organic life, whether infectious or not; it is therefore _more_ than disinfection, which destroys the germs of infection alone. A =Disinfectant= is an agent which destroys germs of infection. A =Germicide= is the same; an agent destroying germs. An =Insecticide= is an agent capable of destroying insects; it is not necessarily a disinfectant, nor is a disinfectant necessarily an insecticide. An =Antiseptic= is a substance which inhibits and stops the growth of the bacteria of putrefaction and decomposition. A disinfectant is therefore an antiseptic, but an antiseptic may not be a disinfectant. A =Deodorant= is a substance which neutralizes or destroys the unpleasant odors arising from matter undergoing putrefaction. A deodorant is not necessarily a disinfectant, nor is every disinfectant a deodorant.