FOOD AND DRINK. 75 



the waters at Saratoga, contain three hundred grains and 

 more to the gallon. 



33. Action of Water upon Lead. The danger of 

 using water that has been in contact with certain metals is 

 well known. Lead is one of the most readily soluble, and 

 probably the most poisonous of these substances in common 

 use. When pure water and an untarnished surface of lead 

 come in contact, the water gradually corrodes the metal, 

 and soon holds an appreciable quantity of it in solution. 

 When this takes place the water becomes highly injurious: 

 the purer the water, and the more recent the use of the 

 metal, the greater will be the danger. 



34. In cities, lead pipes are commonly used to convey 

 water through the houses ; lead being also used in the con- 

 struction of roofs, cisterns, and vessels for keeping water 

 and other liquids. After the articles of lead have been in 

 use several months, the danger of lead-poisoning dimin- 

 ishes. An insoluble coating of the sulphate of lead forms 

 upon the exposed surface, thus protecting it from further 

 corrosion. It is, however, a wise precaution, at all times to 

 reject the water or other fluid that has been in contact 

 with leaden vessels over night, or for a number of hours. 

 Allow the water in pipes to run freely before using. 



35. Coffee. This is an important addition to diet, and 

 if moderately used is beneficial to persons of adult age. 

 As commonly employed, it consists of an infusion in boil- 

 ing water of the roasted and ground berry. The water 

 extracts certain flavoring and coloring matters, but that 

 which gives it its peculiar stimulant qualities is the alka- 

 loid caffein. With most persons its action is that of a 

 gentle stimulant, without any injurious reaction. It pro- 

 duces a restful feeling after exhausting efforts of mind or 



33. What is stated of the action of water upon lead ? 



34. Lead in pipes and other things ? Advice ? What takes place after the arti, 

 cles of lead have been used much ? What is wise ? 



35. Coffee as an article of diet? Of what does it consist? How does the 

 water affect the coffee? The peculiar stimulant ? How does it affect most per 



