Milk. 169 



vanilla which had been used in flavoring, which it was 

 supposed contained the poison, since some lemon ice 

 cream, from the same maker, had not affected those who 

 ate it. To decide if the vanilla was poisonous or not Dr. 

 Vaughan and his assistamt applied a very practical test by 

 swallowing three drops each of it. jSTo ill effects following, 

 the assistant took two teaspoonfuls more. As he remained 

 unaffected, Dr. Vaughan decided that the poison was not 

 in the vanilla, and proceeded to analyse the ice cream. 

 From it he isolated tyrotoxicon, with which he next 

 experimented. This time he did notuse his assistant, but a 

 cat. The cat was affected exactly like the Lawton patients. 



Dr. Vaughan then found that by taking a small portion 

 of the poisonous ice cream, he could, as it were, sow the 

 infection in perfectly fresh milk, and cause the develop- 

 ment of tyrotoxicon in it. To a quart of perfectly fresh 

 milk he added a small piece of the Lawton ice cream and 

 set it in his cellar. Next morning he added another quart 

 of milk and then mixed with eggs and sugar, so as to make 

 a custard. On the following morning Dr. Vaughan tasted 

 the custard and was taken very ill ; not so ill, however, as 

 to prevent him isolating tyrotoxicon and poisoning a 

 kitten with it. At 2 p.m. he took a teaspoonful himself, 

 and was seized with violent vomiting and purging and 

 intense headache. Delighted with the success of his 

 experiment, and feeling a little better at 3 p.m., he took 

 another teaspoonful, with equally satisfactory results. 



Since then other workers have confirmed Dr. Vaughan's 

 conclusions, and there is no doubt that under certain circum- 

 stances a very dangerous poison is formed in milk. It is 

 not a product of the ordinary decomposition of milk, but is 

 evidently caused by a peculiar ferment, which fortunately 

 is only rarely present. In all probability it will be found 

 that this peculiar fermentation is due to some micro- 

 organism. It is very unstable : standing in an open vessel 

 will often cause all trace of it to disappear from a milk in 

 which its presence had previously been shown. It appears 

 to be developed most readily in bottles closely stoppered. 

 And these facts are not without their practical bearing. 



