The following account of the diseases prevalent in Lima is from Dr. Unanue:—
"Heat and humidity are the two great causes of disease in this climate; the first predisposes and the second excites it. The suavity of the climate promotes the pleasures of Venus, and produces those of Ceres, and both contribute to enervate and relax the tone of the human frame. The first symptoms of debility present themselves in the digestive organs, and many infants, constitutionally weak, die of convulsions produced by indigestion: epileptic affections are very common when children begin to eat ordinary food. Young people suffer much from cholics, particularly in autumn, owing to the debility of the stomach, caused by excessive transpiration; indeed the inhabitants of Lima are so well aware of the weakness of their digestive organs, that they attribute every indisposition to empacho, indigestion. Owing to the same constitutional weakness of the stomach, youth are very apt to become afflicted with phthisis and asthma, and many who escape from these affections, if they indulge their passions, are afterwards borne down by obstructions of the abdominal viscera and dropsies, which, owing to the dampness of the climate, are incurable. The functions of the internal and external vessels becoming inverted, those being surrounded by a body of water, these augment it incessantly by absorbing an abundance from the humid atmosphere. Lima is often called el pais de los viejos, the country of old people, because they generally live abstemiously, and instances of extreme longevity are not uncommon."
An extract from medical observations made by Dr. Unanue, in the year 1799, may serve to convey an idea of the particular diseases prevalent during the different seasons, beginning with the month of January, at which time the summer solstice commences.
"In January the small pox made its appearance, hemorrhages and bilious diarrhœas were common; these were followed by eruptive fevers in February. During this and the succeeding month violent catarrhs and coughs were prevalent, particularly among children, and those adults who were affected with asthma suffered very much. In some years, when the summers have been oppressively warm, copious perspirations and lipirias (cholera morbus) have been known to afflict many persons, but they were not observed in 1799.
"During March, April, and the beginning of Autumn, intermittent fevers were very common, particularly the tertian, often accompanied with dysentery; in May and the beginning of June dry and violent coughs were observed, that produced an irritation of the throat and sometimes small ulcers.
"During July quinsies afflicted several people, and cutaneous eruptions (exanthemata milliaria) were frequent, intestinal inflammations and dysentery were also prevalent; and during the months of August and September pulmonic inflammations and pleurisies were frequent.
"Inflammations of the lungs were common during the month of October, as also bilious diarrhœa; during this month the autumnal tertian began to disappear; in November many died of the dysentery, and cutaneous eruptions were very common. Out of 4229 patients received into the hospital of San Andres this year 317 died."
I have observed that syphilis is never very virulent in Lima and on the coasts of Peru, but in the interior, particularly in cold situations, it is more prevalent and more severe.
Berrugas, warts of a peculiar kind, are common in some of the valleys of the coast. They are supposed to be caused either by drinking or being washed by the waters of certain rivers. The first symptoms are most excruciating pains in the legs, thighs and arms (the parts where the warts generally make their appearance), which frequently last for one or even several months. When the warts begin to appear the pain is relieved, and when they burst a large quantity of blood is discharged, the pain ceases, and the patient recovers. No medicines are ever administered for this disease, the natives believing that patience is the only remedy. They carefully keep themselves warm, and avoid wetting themselves, because it often produces spasms, and sometimes death.
In 1803 a new disease made its appearance during the summer in the valley of Huaura, and proved mortal to many individuals, particularly indians and negroes, to whom it seemed to be almost confined; for few or no white people were infected by it. The first appearance was a small pustule, the centre depressed, bearing a small purple spot; as it extended, several other small pustules arose on the edges of the original one, filled with a limpid fluid; these pustules increased to a large size, having the resemblance of blisters raised by burning. If an incision were made in the part affected, no blood flowed, nor did the patient feel the operation; the flesh had a spongy appearance, and a very pale red colour. If not relieved, the patient usually died between the fifth and tenth day, and sometimes earlier. The method of cure adopted was the total extraction of the diseased part, and the application of a poultice. This disease was called by the natives grano de la peste, pest pimple.