10 TOXINES AND ANTITOXINES. 



lence as corresponds to the amount of toxine mechanically 

 adhering to them, and from this they can be freed by washing 

 with a physiological solution of salt. But the cells no longer 

 contain any true toxine, which might presumably be extracted 

 from them by breaking up the cell structure (treatment with 

 alkali), as H. KossEL, 1 for example, was able to prove in the case 

 of diphtheria bacilli. It is true that these dead cells may still 

 contain poison of quite another kind (bacterial proteins), but 

 these have nothing to do with the specific poisoning (vide infra"). 



The phytotoxines are found in the most different organs of 

 plants, and especially in the seeds, from which they can be 

 isolated by extraction with dilute solutions of salt. 



The zootoxines are produced in the secretions and blood of 

 animals. It follows from all this that typical toxines are free 

 secretions substances that are phsiologically thrown off by the 

 cells into the surrounding media. In this respect they are 

 analogous to the true enzymes. Just as the pancreatic glands 

 secrete trypsin, or the glandular cells of the starch layer secrete 

 diastase, so does the cell of the diphtheritic micro-organism 

 secrete diphtheria toxine. 



This can only be stated with certainty, however, for the typical 

 toxines, notably diphtheria and tetanus. In other cases the 

 facts are much more obscure. 



As we shall see later, it is still quite open to discussion 

 whether, for example, the micro-organisms of cholera and typhus 

 produce true toxines in the sense of our definition. Even grant- 

 ing that this is the case, the toxines are certainly not secreted in 

 a free state in any appreciable amount, but are firmly retained, 

 at least, by the living cell. Only when the cell decomposes after 

 death are they liberated to a limited extent, as in the case of 

 older cultivations. But even then the poisonous substances 

 have undergone radical changes, having been converted into 

 secondary, more stable products that no longer show the 

 characteristics of a true haptine. We shall return to this 

 point later. 



A close analogy to this retention of the active substances to 

 the living cells may be observed in the case of certain ferments? 

 We know that the yeast cell, in addition to secreting a small 

 amount of free diastase, also contains a series of other enzymes 

 invertase, maltase, &c. which can only be set free after the 



1 H. Kossel, "Zur Kenntnis des Diphtheriegiftes," Centralbl.f. Bakt., 

 xix., 977, 1898. 



2 Oppenheimer, Ferments and their Actions, English translation by C. 

 Ainsworth Mitchell. London, 1902 (Griffin & Co.). 



