HYGIENE 



2892 



HYGROMETER 



and the care of invalids and children. When a 

 household is conducted according to the prin- 

 ciples 'of hygiene it is safe to expect that the 

 health and happiness of the members of that 

 household will be well guarded. 



Public Hygiene. The health of the public is 

 a subject which received little attention until 

 the beginning of the nineteenth century. The 

 terrible epidemics that formerly swept away 

 vast numbers of victims throughout the world 

 (see CHOLERA) are a proof of the deplorable 

 ignorance that once prevailed concerning sani- 

 tation and its benefits. Each town or city now 

 has its department of public health. It is the 

 duty of the health department to see that the 

 drainage, water supply and ventilation of build- 

 ings are up to the modern standard of excel- 

 lence, that streets are kept free from filth, 

 garbage and other refuse disposed of, street- 

 cars and other public conveyances kept in a 

 sanitary condition, and that laws respecting 

 vaccination and quarantine are enforced. In 

 general, boards of health are established to 

 safeguard the health of the community in 

 every possible way. 



Military Hygiene has to do with the pres- 

 ervation of the health of the soldier. When 

 large numbers of men are in camp or on the 

 battlefield the problem of maintaining sanitary 

 conditions is very serious. The remarkable 

 progress made in military sanitation in recent 

 years is indicated by the comparative absence 

 of epidemic diseases among the armies which 

 fought in the War of the Nations. Because 

 vaccination has become so nearly universal, 

 the armies of Western Europe, though they 

 came into contact with troops from Asia and 

 Africa, were not attacked by smallpox; and 

 that other terrible enemy of the soldier, 

 typhoid fever, was also held in check through 

 the use of vaccine and enlightened methods 

 of sanitation. 



Another striking illustration of what may be 

 accomplished on a large scale by the applica- 

 tion of the laws of hygiene is the work of the 

 United States army in the Panama Canal Zone 

 (see PANAMA CANAL). What was formerly a 

 region infested with disease and filth has been 

 made one of the most healthful spots on the 

 globe. Cuba, too, has been made hygienically 

 safe by means of sanitary measures and the 

 extermination of those dangerous carriers of 

 germs the fly and the mosquito. B.M.W. 



Consult Allen's The Man Wonderful; the Mar- 

 vels of Our Bodily Dwelling; Davison's The Hu- 

 man Body and Health; Jewett's The Body and 



Its Defences; Pyle's A Manual of Personal 

 Hygiene. 



Related Subjects. This important subject is 

 given full treatment in these volumes. The reader 

 is referred to the following articles : 



Gymnastics 



Health 



Health Habits 



Heating and Ventilation 



Home Economics 



Immunity 



Life Extension 



Mastication 



Medicine and Drugs 



Mental Handicaps 



Mosquito 



Nutrition 



Physical Culture 



Quarantine 



Sanitary Science 



Sewer and Sewerage 



Teeth 



Vaccination 



Antitoxin 



Athletics 



Baby 



Baths and Bathing 



Board of Health 



Breath and Breathing 



Child 



Cookery 



Dentistry 



Diet 



Digestion 



Disease 



Education, subtitle 



Hygiene of Education 

 P^atigue 

 Fletcherizing 

 Fly 

 Food 

 Garbage 



HYGIENE OF EDUCATION. See subtitle, 

 in article EDUCATION, page 1944. 



HYGROMETER, higrom'eter, an instru- 

 ment for determining the amount of moisture 

 in the air, or as it is expressed in the reports 

 of the Weather Bureau (which see), the 

 humidity of the atmosphere. Numerous ex- 

 periences tell us that there 

 is more moisture in the air 

 at one time than at another. 

 Clothes hung out to dry 

 will dry very slowly just 

 before or just after a rain, 

 but they dry rapidly on a 

 bright, warm day. Cool 

 days are usually damp and 

 bring clouds and fogs, 

 while warm days are more 

 likely to be clear and dry. 

 This is because the atmos- 

 phere can contain more 

 water vapor at a high than 

 at a low temperature. 

 When it has all that it can 

 contain at a given tem- 



FIG. 1 

 Mason's hygrom- 



perature it is said to be eter, the form which 



T . . .. is most common. 



saturated, and the differ- 

 ence between the amount of moisture that the 

 atmosphere contains at a given temperature 

 and the amount necessary to saturate it is the 

 relative humidity. The hygrometer enables 

 us to determine the relative humidity. 



The hygrometer used by practically all gov- 

 ernment weather bureaus, and also the one 

 most frequently seen, consists of two ther- 

 mometers, attached to the same support. One 



