MATERIALS FROM PLANTS AND ANIMALS 421 



bility to pain in the regions of the body into which it is injected. 

 Quinine, obtained from the bark of the cinchona, or caHsaya, tree of the 

 madder family, another South American plant, is poisonous to the ma- 

 laria Plasmodium in quantities that are harmless to most human beings. 

 Atropin is obtained from the roots and leaves of the belladonna plant, 

 of the potato family ; it paralyzes involuntary muscles, and for this rea- 

 son is often applied to the eyes so as to permit an examination uninflu- 

 enced by the reflexes that would occur with change in illumination etc. 



Musk, obtained from the scent glands of the musk deer, and 

 ambergris, derived from the bile of the whale, have been used 

 as bases for producing perfumes. Spermaceti is also obtained 

 from the whale. Ammonia was formerly obtained largely from 

 horn cuttings and shavings (hence the old name hartshorn), and 

 from the dung of camels and other animals. Cantharides, a 

 local irritant, is obtained from a beetle. Ox gall is used to cor- 

 rect certain conditions in the intestines. Extracts from the thy- 

 roid gland of sheep and other gland extracts are used to remedy 

 various defects in the working of the human organism. 



Many materials used in connection with the care of the "body 

 in health as well as in disease, but not in any sense drugs, are 

 derived in large measure from plants and animals ; rubber, 

 chamois skin, glue, and alcohol are examples. 



312. Materials used as means. Wood, which has so great a 

 variety of direct uses, is also the most common material for the 

 making of many kinds of instruments or tools. It is a large 

 factor in many kinds of vehicles and transportation systems, 

 including boats and railroad ties, and in containers for storage 

 and shipping. Cork and rubber have numberless uses in tools, 

 instruments, devices, and apparatus, including means of trans- 

 portation. Glue, rosin, turpentine, linseed oil, tanning mate- 

 rials (obtained chiefly from the bark of various trees), leathers, 

 and fibers are some of the materials that we use in carrying 

 on the world's work. We use these materials not by consuming 

 them directly as food, or in immediate protection or other serv- 

 ice to the body, but as tools, machines, and other devices that 

 enable us to get things that we need. 



