In each of the three conditions comprised under the general term of _septic infection_ it is not now a question of particular organisms, but of intoxication by products which are more or less common to at least several of them. In a general way, they are mainly _due to the activity of the organisms already grouped as pyogenic_. Those which produce pus are capable of causing septic infection. In addition to these, it is probable that certain of the saprophytes or ordinary putrefactive organisms may produce the same effect. =Symptoms.=--In sapremia the symptoms begin promptly, depend for their intensity upon the dosage of poison, and recede quickly as soon as the source of poisoning is removed or its activity subdued. An instance of the possible causes of sapremia will perhaps best illustrate its pathology. Take, for example, the act of delivery of the full-term fetus. At the completion of this operation there is left a fresh, bleeding wound of large area which is more or less exposed to putrefactive agencies. This is reduced with the contraction of the uterine walls to a comparatively small cavity containing more or less freshly coagulated blood. As long as this clot does not putrefy it is disintegrated inoffensively, to be discharged in large part with the lochia. If germs of putrefaction enter, either during the act of labor or afterward, and linger, putrefactive processes are set up in the clot with the prompt production of certain toxins and ptomains. There is here then a _septic suppository_ with conditions favorable for absorption by the containing tissues. How quickly the poisoning may show itself, and how soon it may subside after removal of the putrefying clot, daily experience may tell. _Sapremia then is intoxication produced by absorption of the results of putrefaction of a contained material within a more or less closed cavity_, whose walls are capable of absorption of noxious products as they form. _As long as putrefaction is essentially limited to the contained mass_, and does not spread to and involve the containing or surrounding tissues the case is one of sapremia. _As soon as the process spreads from the containing tissues the case merges from one of sapremia into one of septicemia._ That this may occur in any case without prompt intervention will be readily understood. Sometimes patients may die of sapremia, though rarely, and in such case ordinarily as the result of gross neglect. Once the septicemic process is begun, however, its spread cannot always be checked, and the case which one day is sapremic and redeemable may later become septicemic and practically lost.