106 FOOD AND DRINK 



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. {Read Note 12.) 



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

 through the houses ; lead being also used in the construction of 

 roofs, cisterns, and vessels for keeping water and other liquids. 

 After articles made of lead have been in use several months, 

 the danger of lead-poisoning diminishes. 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. Coif ee. 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 boiling 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 alkaloid caffeine. With most 

 persons its action is that of a ' gentle stimulant, without any 

 injurious reaction. It produces a restful feeling after exhaust- 



12. Lead in Drinking- Water. "The danger of using lead for pipes 

 or cisterns is now well known, the case of the late royal family of France, 

 at Claremont, having made the matter notorious. In this case there was 

 one-tenth of a grain in the gallon, and one-third of the persons who 

 drank the water were affected. But even one one-hundredth of a grain 

 per gallon has produced palsy in those who drank this impurity habitually. 

 It is remarkable that the Thames water will at one time dissolve lead, 

 and not at another." Mapother's Health Lectures. 



34. Lead ia pipes and other things ? Advice ? What takes place after the articles 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 person^ ? 



