,o20 KANSAS CITY REVIEW OF SCIENCE. 
very much more expensive than what is known as the "separate system," but 
that if we judged by ths experience in other cities, it would also largely increase 
what physicians call ''zymotic " diseases, such as typhoid, diphtheria, scarlet 
fever, etc., a class of diseases from which Kansas City had hitherto been happily 
remarkably free, and which are supposed to be produced by imperfect ventila- 
tion and drainage, and especially by the exhalations of large sewers. - 
At that time there were, if I remember rightly about four and a half miles of 
sewers in the city, while at the present time there must be over twenty miles, so 
that enough has been done in the meantime to give us some data by which to 
form a judgment as to the soundness of the reasoning which was then advanced, 
and if we distrust the experience of others, at least to give us some experience of 
our own. 
Since my return to Kansas City I have been endeavoring to inform myself 
as to what the facts really are, and I find that there is a general impression that 
the city is not as healthy as it was in the early days of its history. I have been 
informed by some of the leading physicians, that there has been an increase in 
zymotic diseases (the much dreaded scarlet fever, typho-malaria and diptheria), 
and that they show a marked difference in type from the same diseases as they 
existed in the days before sewers; but that in few cases only have they been traced 
directly to the effect of the sewers, or to defective plumbing. Other physicians 
again, while admitting an increase in zymotic diseases, attribute it to the increase 
of population, or to the turning up of the soil while carrying on public improve- 
ments in various parts of the city. 
As vital statistics have been kept here much too short a time to permit of 
any comparisons being made, or to form the basis for an actual demonstration of 
the effects of the sewers, I must abstain now from making a positive statement 
upon this branch of the subject, but I hope that the physicians of the city, who, 
both from their experience and scientific training, are the persons best fitted to 
reach sound conclusions on this subject, will favor us with their opinions, and 
with the actual facts occurring within their knowledge. 
Upon one point, however, I believe all persons are agreed, and that is, that 
with a separate system of sewers in which the house refuse shall be confined by 
itself in small pipes, daily flushed for their whole length by automatic means, 
there would be no chance for the development of the so-called sewer gas, and no 
danger of infection from that source. All believe, therefore, that whether the 
."combined system" is really as dangerous as has been represented by sanitar- 
ians elsewhere or not, (he "separate system" would certauily be safer. 
This brings us to consider in what respects these two systems differ from 
each other, and why the one should be thought to be unhealthy, while the other 
is admitted to be safe. Some persons seem to have an idea that the subject is 
intricate and mysterious ; that the two systems differ in the same way as do two 
complicated designs for different purposes, or two plans for some intricate ma- 
chine. In point of fact, however, no subject is simpler or more easily under- 
stood, and the only difference in principle between the two systems, is that in 
