. Adventures with animals and plants. Biology. 330 300 250 200 150 100 50 Co?ista?it Care Is Needed for Health unit vi ll 1 m A vv I \ I s > V N. ^^ 00 o 00 00 00 00 o 00 00 o >^ o o o ^ On C\ OS >r^ O ir\ O "^ i-H tN fN rCi r<^ CS OS CN C\ 0\ Fig. 299 Death rate from diphtheria per 100,000 people in New York City. Co?/!pare the rates of 1882 with 193';. Since which year has there been a steady decrease? Why? (saunders). Fig. 300 The bacillus that causes tetanus (lock- jaw) fornis a spore at one end of the cell. Of what iynportance is this fact? (American mu- seum OF NATURAL H
. Adventures with animals and plants. Biology. 330 300 250 200 150 100 50 Co?ista?it Care Is Needed for Health unit vi ll 1 m A vv I \ I s > V N. ^^ 00 o 00 00 00 00 o 00 00 o >^ o o o ^ On C\ OS >r^ O ir\ O "^ i-H tN fN rCi r<^ CS OS CN C\ 0\ Fig. 299 Death rate from diphtheria per 100,000 people in New York City. Co?/!pare the rates of 1882 with 193';. Since which year has there been a steady decrease? Why? (saunders). Fig. 300 The bacillus that causes tetanus (lock- jaw) fornis a spore at one end of the cell. Of what iynportance is this fact? (American mu- seum OF NATURAL HISTORY) Testing for susceptibility to diphtheria. Some children seem to have a natural immunity to diphtheria. In this respect it is different from smallpox to which none of us seems to be naturally immune. Doctor Schick wanted to avoid unneces- sary immunization. He therefore de- vised a simple test now known as the "Schick ; By means of this, the sus- ceptible children can be discovered. A very small amount of toxin is in- jected into the skin of the arm. After about twenty-four hours a doctor can tell from the appearance of the skin in the region near the injection whether or not the person is naturally immune. If a peculiar red region appears, the results are "positive," that is, the child is suscep- tible, and the doctor recommends immu- nization with toxoid. If the results are negative, immunization is not necessary. Immunization is a safe and cheap insur- ance against diphtheria. And at the same time it helps to protect others in the community. When every child is tested for susceptibility and then immunized if necessary, there will be less diphtheria. Antitoxin against lockjaw. Until re- cently lockjaw or tetanus (tet'an-us), like rabies, meant certain death. Unlike most other pathogenic bacteria, the germ that causes the disease can form a spore. In this form it can live for a lon^ time without the warmth and food of the ani- mal's body. Tetanu
Size: 1635px × 1529px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookpublisherbostondcheath, booksubjectbiology
