Other indications of the presence of pus are a well-marked leukocytosis, coupled with the iodine reaction indicating the existence of glycogen in the blood, the presence of indican in the urine, and the positive results frequently obtained by making cultures from the blood. When pyogenic bacteria are found in the blood the inference is very plain, and both treatment and prognosis are influenced. In such a case the introduction into the blood of an antiseptic such as Credé’s soluble metallic silver or of the antistreptococcus serum, is plainly indicated. The absence of bacteria from the blood, under these circumstances, does not disprove the presence of pus, but their presence gives a very serious character to the disease, and should lead to a most guarded prognosis. Invasion of the blood by staphylococci is nearly twice as serious as when streptococci gain entrance. Suppuration of the bones and of the tendon sheaths is liable to produce such invasion. The other disturbance with which suppuration is so often complicated is _septic infection_. In fact it may be questioned whether pyrexia is not an expression of this condition. Any collection of pus, no matter how small, may show signs of septic infection; and, on the other hand, large collections may be formed without serious septic symptoms--in other words, suppuration and expressions of septic infection may be blended in almost every conceivable way. Sepsis as a distinct condition will be described in another chapter. It is important to summarize what may become of pus when once it has formed and is not promptly evacuated. Pus when long present may be-- A. _Absorbed_; B. _Encapsulated_; and C. _Undergo various degenerations or chemical alterations_. A. _The possibility of the absorption of pus_, or, what is equivalent to it, its spontaneous disappearance, has been mentioned. While it does not usually take this course, it may thus disappear; as, for instance, in the anterior chamber of the eye in cases of _hypopyon_, or in various other localities, particularly when present only in small amounts. The absorption of pus is purely a matter, as far as we know, of phagocytic activity plus the power of the tissues to take up various fluids.