202 IOWA ACADEMY OF SCIENCES 



treated by the department of health physicians; in 1897 the 

 average case mortality was only 15 per cent, or more than 

 twice as great as the department cases; and in in 1898 the aver- 

 age case mortality was only 12.5 per cent, but still one third 

 greater than the department case mortality. Hence the total 

 956 deaths represent 4,785 cases; the 702 cases in 1897 and the 

 622 deaths in 1898 represent about 9,000 cases. 



The conclusions from the above are irresistible that Chicago 

 physicians are using antitoxin in the treatment of diphtheria 

 more generally and more successfully than any other similar 

 number of their brethren elsewhere in the world; and that to 

 the facilities afforded by the department and to the cordial co- 

 operation of the profession with the department of health is 

 due the most astonishing results. 



If only the three years before and after the introduction of 

 antitoxin be compared, the decline is still more striking. In 

 1893-95 there were 4,505 deaths from diphtheria and all croup; 

 in 1896-98 there were only 2,552 such deaths — a decline of 

 43 per cent, or an actual saving of 1,953 lives in the last three 

 years as compared with the preceding three years. A promi- 

 nent factor of success in the antitoxin treatment is the early 

 injection of the serum. In Chicago the mortality rate was .28 

 in those treated the first day; 1.67 in those treated the second 

 day; 3.77 in those treated the third day; 11.39 in those treated 

 the fourth day and 25.37 in all cases treated after the fourth 

 day. 



In preparing the blood serum of the immunized horse it is 

 very desirable, of course, to have a uniform standard of 

 strength. One-tenth of 1 c. m. of what Behring calls his normal 

 serum will counteract ten times the minimum of diphtheria 

 poison fatal for a gainea-pig weighing 300 grammes. 1 c. m. of 

 this normal serum he calls an antitoxin unit. 



Parke, Davis & Co., also H. K. Mulford Co., Philadelphia, 

 put up antitoxin serum in bottles which they number 1, 2, 3, 4 

 and 5. No. 1 contains 500 units; No. 2, 1,000 units; No. 3, 1,500 

 units; No. 4, 2,000 units; No. 5, 3,000 units. It has been deter- 

 mined by experimentation that 500 units will immunize the 

 attending physician, or the nurse or members of the family who 

 have been exposed to diphtheria for a period of thirty days. 

 Unless the case of diphtheria seems to be severe, a dose of 1,000 

 units is sufficient if administered the first day of the attack. 

 If this treatment is not given until the second day 2,000 units 



