This sufficiently explains the immunity which adults usually enjoy, and especially those who are most of the time away from home and in the open air.
Typhoid fever has long been known to be caused by sewer emanations. It is quite true that this is not its only source, but it is probable that in all large cities, where sewer-pipes are connected with the houses, sewer-gas causes more typhoid fever than all other causes combined. In the country, also, and especially in the large hotels at fashionable watering-places, examples of sickness and death from this source are alarmingly frequent.
Diphtheria must be classed among the diseases which in all probability are, in many cases, caused or conveyed by sewer-gas. The testimony upon this point is so well-nigh conclusive that many medical men accept it as an established fact. For myself, I do not entertain a doubt upon the subject; and this is the opinion of Professor Willard Parker, as expressed at the Academy.
In the report of the Michigan State Board of Health for 1881 occurs the following passage:
Dr. Janeway, addressing the Academy, said:
Scarlatina.—Professor Barker declared to the Academy that sewer-gas malaria had often, in his experience, been found to complicate scarlatina, and render fatal an attack which might otherwise have ended in recovery.
Dr. Alfred Carpenter, of London, a well-known physician and sanitarian, has in a paper of considerable length, published in "The Sanitary Record," London, for March 15, 1882, related many examples in which scarlatina was propagated, perpetuated, and intensified by sewer-gas; the result of his careful observations being that in many cases, in order to render the scarlatinous germs which came through the sewers capable of successful inoculation, the patients need to have been exposed for some time to the debilitating influences of the sewer-gas; in other words, as he affirms, a suitable soil must have been created in these persons. In a letter addressed to me, dated Duppas