THE GERMS OF DISEASE. XXI 



morning. An absence of salt produces an unhealthy condition of the skin, and, it is 

 supposed, has, at all events in damp countries, like Holland, a tendency to favour 

 the development of worms. Then, again, there may be a deficiency of another kind 

 of food, for the patient may not get enough fresh air, and oxygen is even more 

 important for the maintenance of lifo than beef and mutton. We know that many 

 vegetables, when grown in the dark, lose their colouring matter, and we know how 

 pale and flabby people become who spend their lives in underground, badly-lighted, 

 ill-ventilated kitchens and cellars. In our large over-crowded cities, and more 

 especially in the metropolis, it is no unusual thing to find from seventeen to twenty 

 people living, eating, and sleeping in a room not more than ten feet square. The 

 filthy and miserable appearance of many parts of London can hardly be imagined 

 by those who have not witnessed them. Dickens's description of a London slum is no 

 exaggeration, as we can testify. " Wretched houses," he says, " with broken windows, 

 patched up with rags and paper ; every room let out to a different family, and in 

 many instances to two or even three fruit sellers and 'sweetstuff' manufacturers in 

 the cellars, barbel's and red-herring vendors in the front parlours, cobblers in the 

 back, a bird-fancier 011 the first-floor, three families on the second, starvation in the 

 attics, Irishmen in the passage, a ' musician ' in the front kitchen, and a charwoman 

 and five hungry children in the back one filth everywhere a gutter before the 

 houses, and a drain behind clothes drying and slops emptying, from the windows, 

 girls of fourteen or fifteen with matted hair, walking about barefoot, and in white 

 great coats, almost their only covering ; boys of all ages, in coats of all sizes and no 

 coats at all ; men and women, in every variety of scanty and dirty apparel, lounging, 

 scolding, drinking, smoking, squabbling, fighting, and swearing." Even people who 

 work chiefly by artificial light, as miners and post-office sorters, suffer from a chain 

 of evils which soon bring them below par. They become nervous, depressed, and 

 low-spirited, and in the long run often take to drink. 



There are certain diseases distinctly due to the introduction of some deleterious 

 matter into the system either with the food or air. We are not now referring to the 

 slow poisoning produced by the inhalation of minute particles of arsenic given off 

 by arsenical wall papers, or to other similar cases where the injurious effect is the 

 result of some recognised animal or vegetable poison. We mean rather those 

 equally deadly, but far more subtle poisons, which are the cause, or supposed 

 cause, of many of our fevers, as cholera and typhoid. It has been conclusively 

 proved that the germs of typhoid may be introduced into the organism by means of 

 impure water, and that the poison of cholera and some other diseases may be carried 

 for immense distances by currents of air. What the exact nature of these germ? 

 may be we do not actually know, we have not been able to isolate them, or to 

 recognise them by any chemical or microscopical test, and know them only by the 

 startling effects they produce on the animal economy. We all know that many 

 diseases are contagious, that is, are capable of being transmitted from one person to 

 another. It would serve no useful purpose to discuss the primary origin of the 

 various contagious poisons, or their capability of being re-developed if once 

 exterminated. It is probable that now-a-days the development of any ca^e of 

 contagious disease de novo is infinitely rare, and that in nearly every instance it 



