129 "An infectious disease is one in which disease germs infect (that is, invade) the body from without. Among the infectious diseases are some that are quite directly and quickly conveyed from person to person and to these the term contagious is applied. Formerly a sharp line was drawn between infection and contagion, but to-day it is recognized that no such line exists."—HOUGH AND SEDGWICK, _The Elements of Hygiene and Sanitation._ 130 The arctic explorer, Nansen, states that during all the time that his party was exposed to the low temperature of the arctic region, no one was attacked by a cold, but on returning to a warmer climate they were subject to colds as usual. The difference he attributes to the absence of germs in the severe arctic climate. There seems to be no doubt but that most of our common colds are due to attacks of germs. 131 An interesting biological fact is that the female _Anopheles_, and not the male, sucks the blood of animals and is the cause of the spreading of malaria. 132 The habit of spitting upon the floors of public buildings and street cars, and also upon sidewalks, is now recognized as a most dangerous practice. Not only consumptives, but people with throat affections, may do no end of harm in the spreading of disease by carelessness in this respect. 133 For further information on the care of consumptives, consult Huber’s _Consumption and Civilization_. 134 As typhoid fever is a disease of the small intestine, great care must be exercised in taking food and in the bodily movements. Solids greatly irritate the diseased lining of the intestine, and the weakened walls may actually be broken through by pressure resulting from moving about. 135 Alcoholic beverages include all the various kinds of drinks that owe their stimulating properties to a substance, ethyl alcohol (C2H5OH), which is made from sugar by the process of fermentation. They include _malt liquors_, such as beer and ale, which contain from three to eight per cent of alcohol; _wines_, such as claret, hock, sherry, and champagne, which contain from five to twenty per cent of alcohol; and _distilled liquors_, such as brandy, whisky, rum, and gin, which contain from thirty to sixty-five per cent of alcohol. Alcoholic beverages all contain constituents other than alcohol, these varying with the materials from which they are made and with the processes of manufacture. The distilled liquors are so called from the fact that their alcohol has been separated from the fermenting substances by distillation. 136 Duncan, _The Chemistry of Commerce_. 137 Alcohol is "denatured" by adding substances to it such as wood alcohol, which render its use as a beverage impossible.