1895.] on the Antitoxic Serum Treatment of Diphtheria. 443 



of this method is that the dose necessary to be injected is so large ; 

 but in the loose tissue of the side of the chest, the back, or the buttock, 

 immediately under the skin, the fluid soon disappears. It is hoped 

 that before long, however, the active principle may be separated, and 

 so obtained in smaller bulk. 



So far we have dealt principally with the antitoxic serum as pre- 

 pared by Behring and Roux and by Roux's method, which is certainly 

 attended with comparatively few difficulties; these, however, have 

 the disadvantage that they take from three to six months to give the 

 desired results. In order to do away with this disadvantage, Klein 

 has carried out a series of experiments in which he has been able to 

 obtain serum of considerable activity in as short a period as 23 days. 

 Instead of introducing the poison only, he adopts the plan used by 

 Behring and Roux in their earlier experiments, of injecting living 

 bacilli which have lost a certain degree of their activity, usin<* 

 for this purpose old cultures. He afterwards introduces toxine 

 along with more virulent bacilli, and thus obtains in the animal 

 such a degree of immunity that it is enabled to withstand, or to react 

 very slightly to more than, a fatal dose of diphtheria bacilli. By 

 the third week the animal will bear the injection of large quantities 

 of virulent bacilli, and by the end of 23 or 26 days the serum has 

 acquired such antitoxic properties that 1 c.c. of it will protect 40 to 

 80 guinea-pigs against a lethal dose of living diphtheria bacilli. It 

 is difficult to compare these results with those obtained by Roux and 

 Behring, but Klein's serum has been used with marked success in 

 certain cases of diphtheria. It appears to have a special power of 

 causing the membrane to clear away, and so to remove the manu- 

 factory of the poison, as on this membrane the diphtheria bacilli 

 accumulate. This method is mentioned as one that may be used 

 especially where it is desired to obtain antitoxic serum quickly. 



Smyrnow has suggested quite a different method of preparing 

 antitoxine. Under Nencki's advice he passed electric currents through 

 the serum of animals, and was thus able to endow it with a certain 

 immunising power. But he was still more successful in obtaining 

 powerful antitoxine by electrolysing diphtheria bouillon cultures; 

 curiously enough, the more virulent the culture the more powerful 

 was the antitoxic substance he obtained. When this antitoxic sub- 

 stance was injected into a rabbit, which 24 hours before had received 

 about J c.c. of a two or three days old diphtheria bouillon culture, 

 there was a rapid rise of temperature followed by marked improve- 

 ment in the condition of the animal. This observer believes that 

 antitoxine can be obtained by this method that will be much more 

 suitable for the treatment of the human subject than that obtained 

 by the ordinary methods. His experiments, however, are far too few 

 to carry any great weight, though they open up a most interesting 

 field for future investigation. 



Assuming now that the antitoxic serum is available, how is it to 

 be used ? It has been strongly recommended that it should be used 



