303. 304. If a drop of an infusion charged with bacteria be put in the extract of beef or mutton, what is the result? What would be the effect upon an open wound? Give Dr. Tyndall's personal experience. Name some efficient antidote against the bacteria of putrefaction. _Ans_. Carbolic acid solution is extensively used for this purpose. How are disease germs often disseminated? State the necessity of disinfection in regard to soiled clothing. 305. Illustrate how disease has been communicated by clothing. What is the first necessary condition to a sanitary home? What is the meaning of the word malaria? What are three active agents in the production of malaria? A fourth? Describe a typical malarious locality. How does newly broken ground induce malaria? 306. State the different ways in which running water can be contaminated. What care should be taken in regard to the level of building site? 307. Give some of the results of a wet foundation. What rules should be observed in regard to shade? What is the effect of too dense foliage about a dwelling? In building a house, what precautions should be taken against dampness? What about the cellar? Sewerage? Plumbing? Ventilation? Fireplaces? Piazzas and balconies? Sleeping rooms? 308. What general purpose does a house serve? What care should be taken in regard to the dust or ash heap? What is the effect if liquids or table refuse be thrown upon it? Where should it be situated? How often should refuse be carted away? If its frequent removal be inexpedient, what precaution should be used? What are the best of all deodorizers? How should the back premises be cared for? What is the best way to dispose of household garbage? 309. How can this be done? With what additional advantage? Give Dr. Derby's remarks in regard to sewers, their condition, and the results. How should traps and drains be cared for? How should bad smells be treated? Is a foul smell always the most dangerous? How do poisonous gases often find entrance to a house? What rule should be observed in regard to ventilating and soil pipes? 310. What precautions should be observed in digging about a dwelling? How do waste pipes often become closed? How may they be cleared? What dangers arise from unventilated waste pipes? How are washbasin pipes contaminated? Tell what came from a neighbor's cesspool. Can you name similar instances which have come under your own observation? 311, 312. Describe the condition and effects of a neglected cellar. Tell what came from a crack in a cellar wall. 313. What effect have brick and mortar in keeping out gases? How do bed coverings take the place of day garments? What kind of bed covering is desirable? Is a comfortable bed necessary to perfect health? How often and for how long time should a bed be ventilated? THE CIRCULATION.