loO PROF.' ATTFIELD — POISONS NOT ALWAYS POISONS. 



from the, to us, poisonous extract of nux-vomica, and the whole 

 colony of which he was a member, had eaten a very considerable 

 quantity of the extract. On carefully separating a piece, and 

 putting it into a glass vessel with a large number of the animals, 

 and setting it by for a few weeks, I found that at the end of the 

 time they had eaten nearly the whole of the lump. It was quite 

 obvious therefore — for I analysed the nux-vomica extract and 

 found it was strong and good — that the mites were living and 

 thriving on strychnine, one of the most virulent of poisons to man, 

 and animals generally. This seemed to me particularly remarkable ; 

 and with my natural taste for experimental science, I proceeded 

 at once to put some of these animals on to pure strychnine. I 

 powdered up some strychnine as finely as I could, and shut up 

 several of the little creatures with it, to determine whether they 

 could eat it and thrive or would die. In those days — nearly 

 twenty years ago — there was no Vivisection Act ; over-legisla- 

 tion had not gone so far as that, or I might have been prosecuted 

 for cruelty to animals. Well, they ate it with avidity, and grew 

 and thrived and multiplied, little, if any, slower than in their old 

 home. So I thought it was pretty clear that I had found some 

 animals to which virulent poisons such as strychnine were, as one 

 might say, bread and cheese. One's tendencies induced one to 

 endeavour to ascertain whether the nux-vomica mites, living on 

 strychnine, would live on our bread and cheese also. I treated 

 them to some Stilton cheese, and they ate it with avidity, and 

 grew on it. So, looking at things from a human point of view, I 

 was led to inquire whether, these poison-mites I'elishing cheese, 

 cheese-mites would relish poisons. I procured a pillboxful from 

 a cheesemonger, and at once set to work to induce them to eat 

 strychnine, morphia, and some rare poisons. They all died. You 

 . see the change of diet was too sudden. I therefore mixed up 

 some cheese with 10 per cent, of strychnine. Cheese-mites ate 

 that quite easily. I then gave them 25 per cent., and they lived 

 and thrived on that ; then 50 per cent. Perhaps I was not patient 

 enough ; the half-cheese half-strychnine killed them. I then 

 again tried similar experiments with the other mites, and found 

 that they would eat these poisons to almost any extent — live for 

 months on cheese containing pure strychnine or pure morphia. 



It was suggested to me to make some experiments on other 

 animals. Well, I tried the poisons on animals almost as common — 

 in London at all events — as mites : on black beetles. I thought 

 they were fair game, and think so still — in spite of a soft heart and 

 the Vivisection Act. I did not get on Avith black beetles. Perhaps 

 they possess a nerve-organisation somewhat similar to our own, 

 and different to that of mites, for they are thrown into violent con- 

 vulsions and get killed by strychnine.* 



* Possibly insect larvso freely eat so-called poisons. See ' Pharmaceutical 

 Journal,' May, 1862, p. 580. Toads and frogs are said to be indifferent to the 

 action of prnssic acid. See 'Pharmaceutical Journal,' March, 1862, p. 456. 



