The value of an active liver is not appreciated by most surgeons to the full extent. The blood of the _portal vein_ is so much more toxic than that of the _hepatic vein_ that it is evident that the function of the liver is to purify and remove the toxic material from the blood that comes from the intestines. This has been called by Flint and others the _depurative action_ of the liver. The activity of the liver also may be proved by grinding up a freshly removed liver with alkaloids, whereby the latter are chemically changed. That the facts above stated, or others related thereto, have not been lost sight of by surgeons is shown by such expressions as _septic enteritis_, _enterosepsis_, etc., which are used by various writers. In previous publications the writer has made a separate topic of so-called _intestinal toxemia_, which he has preferred to introduce here as one of the many possible auto-intoxications. It is a condition not always permitting of exact definition, nor, still less, can the exact toxic agency be indicated in a given case. Nevertheless, it has been made plain that there is perhaps no condition which so _predisposes to sapremia_, _septicemia_, or even _pyemia_ as this vague condition of intestinal toxemia, which, notwithstanding, is so often present. Many surgical patients present forms of blood poisoning in which the poison has _not_ proceeded from the wound, for which the surgeon is not responsible, except that he may have neglected to avail himself of certain precautions. The auto-intoxications, then, which have peculiar interest for the surgeon may be conveniently classified as follows: 1. Those caused by failure in the function of particular organs; _e. g._, myxedema, cretinism, and cachexia strumipriva from thyroidal failure; pancreatic diabetes, where the islands of Langerhans are invaded (interstitial pancreatitis, _q. v._); Addison’s disease from adrenal failure (this being at present the prevailing belief). 2. Those caused by general disturbance of metabolism, where its incomplete or abnormal products reach the general circulation, _e. g._, oxaluria, gout, diabetes. (See Diabetic Gangrene.) 3. Those caused by retention in particular organs or tissues of disturbed metabolic products, _e. g._, the toxemias following serious burns and many septic conditions. 4. Those due to excessive formation of more or less normal products, _e. g._: (_a_) _Hydrothionemia_, _i. e._, the presence of hydrogen sulphide in the blood. This results from one form of gastro-intestinal putrefaction and causes violent symptoms with evidences of hydrogen sulphide poisoning. It is seen in some cases of gastric dilatation, especially those caused by pyloric obstruction (_q. v._).