GLOSSARY 593 



host, host. The organism upon which a parasite lives. 



humidifier, hu-mld' i-fl-er. A device for increasing the moisture of indoor 



air. 

 humidity, hu-mld' i-ty. Moisture or dampness. Condition of air as 



regards moisture, 

 humus, hu' mus. The organic matter of the soil, usually giving it a 



dark color, 

 hurricane, htir' i-can. A violent storm of the cyclone type occurring 



in the West Indies, 

 hydrant, hy' drant. A discharge pipe connected with a city water main 



for fire fighting, 

 hydraulic, hy-dra/ Vie. Pertaining to water under pressure, as hydraulic 



pressure, 

 hydrocarbon, hy" dro-kar' bon. A compound composed of hydrogen and 



carbon, 

 hydrochloric acid, hy" dro-klo' rl as' Id. A compound of hydrogen and 



chlorine, 

 hydrometer, hy-drSm' e-ter. An instrument for determining the density 



of liquids, 

 hydrophyte, hy' dro-flt. A plant which lives in water or water soaked 



ground. 



hypha, hy' fa (pi. hyphae). The thread-like parts of a fungus, 

 hypocaust, hyp' o-east. Basement chambers and flues used for heating 



Roman buildings. 



Imhoff, Im' h6f. Inventor of a certain form of septic tank, 

 immunity, I-mu' ni-ty. Freedom from liability of a disease, 

 incandescent, In" kan-deV Snt. White or glowing from heat, 

 inclemency, In-elgm' en-cy. Harsh, severe, rigorous, applied to weather 



or climate. 



infection, In-feV shon. To be inoculated with disease organisms, 

 infiltration, In" fil-tra' shon. Passing of liquids through small openings, 

 inhalation, In" ha-la' shon. Breathing in. 

 inocculate, In-6V yu-lat. To put disease organisms into the body of an 



animal or plant, 

 inorganic, In" 6r-gan' ie. Not organic. Not formed by or pertaining to 



an organism, 

 insulation, In" su-la' shon. Surrounding a body with non-conductors, 



as of heat or electricity. 



interurban, In" ter-ur' ban. Between cities, applied to electric railroads, 

 iodine, I' o-dln A bluish-black, crystalline element, used externally as a 



medicine. 



irrigate, Ir' i-gat. To water land by artificial means, 

 isolated, Is' o-lat" ed. Separated from others. In a detached place. 



