with the street sewer. Two of these, e and f, were drained from the cellars by cement pipes four inches in diameter, the slops from the houses being thrown upon the ground. The house g was drained both from the cellar and by a branch pipe, untrapped, leading to an open sink by the side of the kitchen door. Two of these houses were the sixth and seventh in the order of invasion by the fever. There can be but little doubt in the event of heavy rains and sudden change of temperature that sewer-gas escaped into these houses. I never was able to detect such an escape of gas, but I concede the fact from what I know of city sewerage. If, however, we accept the explanation of the propagation of the fever after its first introduction in the person of Otto Schmidt by means of the sewer-gas, we leave unexplained a very important circumstance. In the group of infected houses but three out of seven were connected with the street sewer, so that in this particular outbreak sewer emanations are not competent to explain the extension of the disease. We may throw yet further doubt on the sewer theory by the fact that in the cottages M, containing numerous inmates, we have a group of uninfected houses, three of which were directly connected with the same sewer. If we were seeking for the cause of typhoid fever in defective drainage we should select these uninfected houses, as they not only had untrapped sewer pipes in the kitchens, which were practically the living-rooms of the families, but they were built at the foot of the slope and received the surface-wash of the rich alluvium of the hill to the west. Notwithstanding these unhygienic conditions and the actual existence of seventeen cases of the disease on the other side of the street, we find here complete immunity. When we have considered what this fever-poison really is, we shall be in a position to understand the origin of the disease from this source.
In seeking for a cause of the rapid spread of the fever in decomposing matter we are still at fault. The houses were all new, none of them having been built longer than five years. About none of them was found anything like an accumulation of refuse matter. They were careless about disposing of the water from wash-tubs and what is familiar to every housewife under the name of "dish-water"; but these were disposed of with more care than usual, as owing to the dry weather they were scattered over the gardens. In the condition of the vaults a critical inspector could find fault, yet they were in as good condition as these very defective household appendages usually are. Admitting a focus of infection at the house of Otto Schmidt, it is difficult to conceive of such a wide diffusion of the virus as to suddenly establish a focus at each of these seven points. This, however, is one of the least of the difficulties met with in tracing the disease to the decomposition of animal or vegetable matter. In typhoid fever we have a specific disease; that is, it exhibits a well-defined and uniform manner of beginning, a culmination and decline equally well marked, and, taken together, a group of symptoms and anatomical lesions that define
