Trofessor Gamgee on Unwholesome Food. 385 



PROFESSOR GAMGEE ON UNWHOLESOME FOOD. 



Animal poisons still constitute one of the most obscure pro- 

 blems with which chemistry and physiology have to deal. 

 When the Tsetze fly, mentioned by Dr. Livingstone, kills his 

 victim the horse by a wasting disease, how small in quantity 

 must be the morbific matter, which, working we know not 

 how, deranges the vital processes of nutrition and assimilation, 

 and modifies the condition of all the fluids in the great body 

 of the unhappy brute. When a German village suffers from 

 the influence of the peculiar virus developed in badly pre- 

 pared sausages, or when a dish of mussels torments the ad- 

 mirers of that questionable variety of mulluscous food, our 

 analysts fail in their efforts to separate the peccant matter 

 from the general mass, and our physicians are not more success- 

 ful in the endeavour to explain the precise mode in which 

 disease or death may supervene. We look to the general law 

 that " a molecule in motion tends to communicate similar mo- 

 tions to other molecules within its influence/' as expressing 

 what probably takes place in the class of facts with which we 

 have to deal; and although we may in some cases be able to 

 discriminate between the varying amount of danger attending 

 different stages of putrefaction, we cannot define the precise 

 conditions in which a decaying substance exists, when it is 

 invested with the highest amount of deleterious power. Of- 

 fensiveness to the sense of smell is no criterion, because 

 sulphuretted hydrogen, and other gases, which make a violently 

 unpleasant appeal to our olfactory nerves, are capable of exist- 

 ing quite independent of any organic poison, or miasma, which 

 may or may not accompany them according to the circumstances 

 of the case. 



When we have to deal with a preparation of arsenic, to- 

 bacco, opium, or any substance employed in medicine or 

 the arts, we are able to extract a definite material which has 

 little or no tendency to undergo further change, unless it is 

 brought into contact with other bodies under certain conditions. 

 Thus arsenious acid may be preserved unaltered for an indefinite 

 period; the oil of tobacco, or the alkaloids of opium will remain 

 unchanged in our bottles; but when putrefaction assails an 

 organized structure, the morbific power that is evolved, lies in 

 the peculiar motions and changes which influence the ultimate 

 arrangement of particles, and in the operation which they exert 

 upon other substances susceptible of similar alterations in their 

 condition. There is also another consideration that we must 

 bear in mind, and which results from the complex arrangement 

 of atoms in the organic world, or in products which may be 

 derived therefrom. As an illustration of this complexity, let 



