All these fevers are regarded from the standpoint of Humoralism, and depend upon variations in the quantity, quality, mixture or location of the four humors, blood, phlegm, bile and black-bile (_melancholia_). In the general treatment of febrile diseases, so-called preparatives and digestives are first employed to ripen the humors, after which evacuatives (emetics, cathartics, sudorifics, and occasionally even venesection) are utilized for the discharge of these peccant humors. Much emphasis is laid upon the dietetics of fevers, and this branch of treatment is highly elaborated. Complications are met by more or less appropriate treatment, and the condition of the urine is studied with great diligence. Venesection is recommended rather sparingly, and is never to be employed during the _dies caniculares_ (dog-days) or _dies Aegyptiaci_, nor during conjunctions of the moon and planets, nor upon the 5th, 15th, 17th, 25th, 26th, or 27th days thereafter, etc. Among the complications of fevers discussed by Gilbert, two seem sufficiently important to justify special attention. On folio 74b we find a section entitled "_De fluxu materie per parotidas venas_," in which he remarks that "Sometimes matter flows through the parotid veins behind the ears down to the neck and nares, and obstructs the passages for air, food and drink, so as to threaten suffocation." He cautions us against the use of repressives, "lest the matter may run to the heart," and recommends mollitives and dissolvents, such as butter, dyaltea, hyssop and especially newly shorn wool (_lana succida_), which, he says, is a strong solvent. Is this a reference to the septic parotitis not unfrequently seen in low fevers? The following section, "_De inflatione vesice et dolore ejus_," discusses the retention of urine in fevers, and its treatment. Gilbert says: "Inflation of, and pain in the bladder are sometimes symptoms of acute fevers, since the humors descend into and fill the bladder." If this occurs in an interpolated (remittent) fever, he directs the patient to be placed in a bath of a decoction of pellitory up to the umbilicus, "_et effundet urinam_." If the complication occurs in one suffering from a continued fever, the bath should be made of wormwood and a poultice should be placed over the bladder and genitals, "_et statim minget_." The same effect may be produced by poultice mixed with levisticum (lovage) or leaves of parsley. Singularly enough the catheter is not mentioned, though this instrument, under the medieval name of _argalia_ (cf. French algalie), is noticed frequently in the section devoted to vesical calculus.