526 COLLECTED STUDIES IN IMMUNITY. 



to practically zero. In this case then, just as Gruber states, the 

 water has acted as an antitoxin. On the addition of more water 

 to the mixture, however, the iron is again attacked. In fact the 

 more water now added the stronger becomes this action. We thus 

 obtain the curious result that in small doses water acts as antitoxin, 

 while in large doses it increases the action of the poison, surely an 

 interesting problem for Dr. Phantasus! 



This is merely one of the special instances of the fact thus far 

 unexplained, that the different hydrates of sulphuric acid, or their 

 mixtures, manifest a most extraordinary variation of properties- 

 I may refer the reader to the minute and fundamental study of 

 Knietsch, 1 in which the variations of the properties of sulphuric 

 acid at different concentrations have been represented in the form 

 of a curve for many of these properties, thus specific heat, electric 

 resistance, boiling point, vapor tension, viscosity, capillarity, action 

 on iron, etc. A glance at this chart gives one the impression of 

 chaos, and at once shows that on these complicated problems only 

 deep studies can lead to any results, and that the ten-minute experi- 

 ments made by Phantasus-Gruber-Pirquet are absolutely worthless. 

 This is especially true in Gruber's case, which deals with an obscure 

 reaction in which oxidation, abstraction of water, cleavage and sul- 

 phurization take part. Hence I deny that crude experiments of 

 this kind can be used to gain an insight into such an entirely different 

 subject, or that the conditions there observed can even be com- 

 pared to the minutely differentiated processes of toxin-antitoxin 

 combination. 



We shall next take up Gruber's experiments which deal with 

 the hsemolytic action of water, since to persons at a distance these 

 might give the impression that they really have something in com- 

 mon with studies in hsemolytic toxins. The experiments are sup- 

 posed to show that water is composed of an infinite number of differ- 

 ent poisons. Let us listen to Gruber for a moment: 



" Pure water exercises a very great osmotic pressure on red 

 blood-cells, leading to their swelling and to the escape of hemoglobin. 

 Hence water is a toxin for the erythrocj^tes, salt is an antitoxin. 

 When successive amounts of salt are added to the water this toxicity 

 is gradually lost, for the affinity of the water, and with it the osmotic 

 pressure, is thus gradually decreased." 



1 Bericht d. deutsch. chem. Gesellschaft, 1901, page 4069. 



