178 METALS USED IN THE HOME 



wires, barbed wire, iron for various household and industrial 

 uses, are galvanized, or dipped into molten zinc. 



Zinc is an important element in the battery which furnishes 

 the electrical current for ringing our doorbells. 



Lead. The pipes which bring water to our homes and which 

 carry away the wastes are usually of lead. The metal is 

 soft and can be easily bent and cut by the plumber. Lead is 

 rolled into sheets and used as a lining of tea chests and tea cans, 

 and as a lining for tanks and cisterns. Sometimes it is rolled 

 into fine sheets and used as lead foil. It is also made into 

 bullets and shot, and mixed with tin to form solder. 



Compounds of lead are poisonous to the body. Lead is acted 

 upon by acids, even those which are present in dilute form in 

 foods, and the compounds formed from the reaction are dan- 

 gerous. For this reason, cooking utensils should not be made of 

 lead, and should not be soldered together, since solder contains 

 lead. 



Ordinary water acts very slowly upon lead, and hence water 

 which flows rapidly through lead pipes is not injured. But if 

 water remains undrawn in pipes for long periods, the lead is 

 continuously acted upon, and dangerous compounds may accu- 

 mulate in the water. After vacations, however short, water 

 should be allowed to run freely until all pipes are completely 

 empty of their standing water. The fresh supply will be safe. 



Water which contains carbon dioxide and organic matter 

 acts upon lead, and rapidly forms compounds injurious to 

 health. When the city's water supply contains these sub- 

 stances, lead pipes cannot be used with safety. Either the 

 water supply must be abandoned and a new source found, or 

 different pipes must be installed. 



Alloys. Very often different metals are melted together to 

 form new substances or alloys more suited to our needs. The 

 wonderful bronze bnsts and ornaments are made of an alloy, 



