NATURE OF THE TOXIN 363 



has much greater resistance to heat. One striking fact, discovered 

 by Roux and Yersin, is that after an organic acid, such as tartaric 

 acid, is added to the toxin the toxic property disappears, but that 

 it can be in great part restored by again making the fluid alkaline. 



Guinochet showed that toxin was formed by the bacilli when 

 grown in urine with no proteid bodies present. After growth 

 had taken place he could not detect proteid bodies in the fluid, 

 but on account of the very minute amount of toxin present, 

 their absence could not be excluded. Uschinsky also found that 

 toxic bodies were produced by diphtheria bacilli when grown in 

 a proteid-free medium. 1 It follows from this that if the toxin is 

 a proteid, it may be formed by synthesis within the bodies of the 

 bacilli. Brieger and Boer have separated from diphtheria cultures 

 a toxic body which gives no proteid reaction (vide p. 166). 



Toxic bodies have also been obtained from the tissues of those 

 who have died from diphtheria. Roux and Yersin, by using 

 a filtered watery extract from the spleen from very virulent cases 

 of diphtheria, produced in animals death after wasting and 

 paralysis, and also obtained similar results by employing the 

 urine. The subject of toxic bodies in the tissues has, however, 

 been specially worked out by Sidney Martin. He has separated 

 from the tissues, and especially from the spleen, of patients who 

 have died from diphtheria, by precipitation with alcohol, chemical 

 substances of two kinds, namely, albumoses (proto- and deutero-, 

 but especially the latter), and an organic acid. The albumoses 

 when injected into rabbits, especially in repeated doses, produce 

 fever, diarrhoea, paresis, and loss of weight, with ultimately a 

 fatal result. As in the experiments with the toxin from cultures, 

 the posterior limbs are first affected ; afterwards the respiratory 

 muscles, and finally the heart, are implicated. He further found 

 that this paresis is due to well-marked changes in the nerves. 

 The medullary sheaths first become affected, breaking up into 

 globules; ultimately the axis cylinders are involved, and may 

 break across, so that degeneration occurs in the peripheral 

 portion of the nerve fibres. Such changes occur irregularly in 

 patches, both sensory and motor fibres being affected. Fatty 

 change takes place in the associated muscle fibres. There may 

 also be a similar condition in the cardiac muscle. The organic 

 acid has a similar but weaker action. Substances obtained from 

 diphtheria membrane have an action like that of the bodies 



1 Uschinsky 's medium has the following composition : water, 1000 parts ; 

 glycerin, 30-40 ; sodium chloride, 5-7 ; calcium chloride, "1 ; magnesium 

 sulphate, '2- '4 ; di-potassium phosphate, '2- '25 ; ammonium lactate, 6-7;- 

 sodium asparaginate, 3-4. 



