1. In _the period of infection_ (which is commonly the forerunner of the other forms of the plague) the contagion, less active and virulent, keeps lurking in the body, and produces the following symptoms, viz. sharp, flying pains in the glandular parts (such as the armpit and groins) and in the muscles of the neck and breast; ardor urinæ; drowsiness; an increased secretion of the sebaceous humour, so that the skin is in many parts, and more especially in the hands and face, much more unctuous and glossy than usual; the belly is costive, but when moved, there comes away a great quantity of pulpy slimy fæces; the patients complain of a heaviness of the body (some compare their limbs to a mass of lead), great lassitude and faintings. A swelling, but without much pain, of some gland (in the groin or armpit) together with dark-red or brown spots, denote a higher degree of infection: and a bad taste in the mouth, a viscidity of the saliva, loss of appetite, whiteness and foulness of the tongue, and head-ach, show that the patient is going to be attacked with the plague under one or other of the following types. The above-mentioned symptoms, which continue for a longer or shorter time (in some instances for several days or even weeks) are not accompanied with fever. 2. After the period of infection above described has continued for some time without yielding to medicine, it generally ends in _the slow type of the plague_, which is characterized by the following symptoms; viz. shiverings, followed by a moderate degree of heat[42], a febrile[43], unequal, for the most part weak, and often intermitting pulse; a constant dull pain in the head (rather, according to the expression of some patients, a heaviness, as if the head was full of lead); urine pale and turbid, but without sediment; tongue foul and moist; very little thirst; depression of spirits; belly costive during the first three or four days, with inflation of the hypochondria and borborygmi, but the abdomen feels soft on pressure; there is frequent nausea and vomiting of a slimy greenish-yellow faburra[44]; petechiæ and other eruptions[45] make their appearance, in some sooner in others later; but in some they are altogether wanting. The rudiments or germs of buboes and carbuncles, which were forming during the period of infection, now gradually increase in size, but without being accompanied with violent pain; and new ones arise in other places; which, if they suppurate on the fifth, sixth, or seventh day, save the life of the patient: on the other hand, if no suppuration takes place, and great debility, diarrhoea, and delirium come on, the disease terminates fatally, not, however, in some cases till after the fourteenth day.