364 APPENDIX 



doubt, a sufficiency of water to fill the trap, additional water should be 

 poured in. Traps are of various sizes, and of an infinite variety of pat- 

 terns and patents, and must vary greatly according to their situation ; 

 but one thing should be made sure of in their use namely, that they 

 hold not less than two inches of water as a " seal." 



There is at almost all seasons of the year an upward, because warmer, 

 current of air through the main pipes. It is therefore better to have a 

 fresh-air inlet pipe near the point where the drain leaves the house- wall. 

 This helps to prevent the unsealing of traps. It also brings about a 

 purer condition of the air in the interior of the system of pipes so use- 

 ful in this air-current through the soil-pipe that if applied there is little 

 danger of the escape of sewer gas into the living rooms. 



What is sewer gas or sewer air ? It varies greatly in different places 

 and at different times. It is not a definite gas, like oxygen, nitrogen, 

 etc., but varies .in composition, and what is still more worthy of note, it 

 varies in its dangerous qualities. It is not always offensive, although it 

 is generally so ; its odor has been described as being " sweetish and sick- 

 ish." Its dangerous qualities have not yet been determined by chemistry 

 or the microscope, but one practical point may be borne in mind 

 namely, that when a case or cases of contagious disease occur in any 

 hoTjse along any given line of sewer pipes, it is best to use disinfectants 

 in the drainage of the other dwellings along the same line of sewer. 

 Children should avoid playing over or around the sewer-gratings in the 

 streets at all times, and especially when scarlet fever and like contagious 

 diseases are known to' be in the neighborhood ; for the exit of sewer air 

 at these points is always very free, unless it be directly after rainfall. 



One other point must be remembered that the best-laid system of 

 house-plumbing is not indestructible. In the course of time, defects will 

 arise, breaks will occur ; for this reason it would be well for every house- 

 holder to have an examination made at intervals, of every joint and along 

 the whole line of the house connection with the sewer or drain. 



It is thought by many that sewer gas is not found in the country 

 because there are no sewers they have been misled by the word. If 

 the words "drain air" or "filth gas" had been adopted, the universal 

 production of this injurious substance, in close connection with every 

 abode of man, wherever located, might have been better understood. In 

 country houses there are, perhaps, fewer dangers of contamination of the 

 air we breathe by waste products, because there are fewer water-closets, 

 wash-basins, sinks, etc. , and the rooms are less exposed to impure air. 



But in the country danger is apt to come by or through the pollution 

 of the water supply. The well, which furnishes that cool and refreshing 

 draught, is the point to be watched. It is convenient to have the well near 

 the house, because when the snow is on the ground and the weather is 

 cold, the distance to the well from the house is a matter of no small 



