304 PA THOGENIC BA CTERIA . 



The strongest serum ever obtained by the author con- 

 tained 1400 units per cubic centimeter. 



As the quantity to be injected at each dose diminishes 

 according to the number of units per cubic centimeter 

 the serum contains, it is of the highest importance that 

 the serums be as strong as possible. Various methods of 

 concentration have been suggested, such as the partial 

 evaporation of the serum in vacuo, but none have 

 proved satisfactory. The latest suggestion comes from 

 Bujwid, 1 who finds that when an antitoxic serum is 

 frozen and then thawed, it separates into two layers, 

 an upper watery stratum and a lower yellowish one; the 

 antitoxic value of the yellowish layer is about three 

 times that of the original serum. 



Ehrlich asserts that 500 units are valueless: 2000 units 

 are probably an average dose, and, as the remedy seems 

 harmless, it is better to err on the side of too much than 

 on that of too little. Fourteen thousand units have been 

 administered in one case with beneficial results. 



The largest collection of statistics upon the results of 

 antitoxic treatment in diphtheria in the hospitals of the 

 world are probably those collected by Prof. Welch, who, 

 excluding every possible error in the calculations, "shows 

 an apparent reduction of case-mortality of 55.8 per cent." 

 One of the most important things in the treatment is 

 to begin it early enough. Welch's statistics show that 

 1115 cases of diphtheria treated in the first three days 

 of the disease yielded a fatality of 8.5 per cent, whereas 

 546 cases in which the antitoxin was first injected after 

 the third day of the disease yielded a fatality of 27.8 per 

 cent. 



After the toxin has set up destructive organic lesions 

 in various organs and tissues of the body, no amount 

 of neutralization will restore the integrity of the parts, 

 so that the antitoxin must fail in these cases. 



The urticaria which sometimes follows the injection 



1 Centralbl. f. Bakt. u. Parasitenk., Sept., 1897, Bd. xxii., Nos. 10 and II, 

 p. 287. 



