| First day. | Died. | Second day. | Died. | Third day. | Died. | Fourth day. | Died. | Fifth day. | Died. | |
| 106° | ... | ... | 3 | 2 | 1 | 1 | 2 | 2 | ... | ... |
| 105° | 9 | 3 | 5 | 4 | 2 | 5 | 2 | 2 | 2 | 2 |
| 104° | 18 | 10 | 23 | 13 | 8 | 3 | 2 | 2 | 3 | 2 |
| 103° | 14 | 4 | 11 | 8 | 2 | 2 | 3 | 1 | 2 | ... |
It will be seen from this table that the danger line of temperature in yellow fever descends as the case progresses.
It may again be stated that yellow fever, like scarlet fever, exhibits such striking contrasts in its mortality-rate that it is hardly possible to assert any average standard. It is true that in this disease, as in all others, statistical accumulations tend to correct their own errors in exact proportion to the magnitude of the collections.
In 1878 some 36,000 cases occurred in Louisiana, of which number not less than 6000 were fatal, a percentage of 16.66. The results of private practice in New Orleans are exhibited in the following statistics: Four of the principal practitioners in the city treated in private practice 975 patients—909 white and 66 colored. Of the former, 92, or 10.11 per cent., died; of the colored only 2 died. The cases and deaths among the whites, classified by age, were as follows:
| AGE. | Cases. | Deaths. | Per cent. |
| Under 5 years of age | 206 | 26 | 12.67 |
| From 5 to 10 years of age | 233 | 20 | 8.61 |
| From 10 to 20 years of age | 183 | 9 | 4.9 |
| From 20 to 40 years of age | 232 | 39 | 16.7 |
| From 40 to 60 years of age | 47 | 6 | 12.7 |
| From 60 to 80 years of age | 4 | 2 | 50 |
The physicians above quoted lived in different parts of the city. All of them extended their visits and professional services to the sick to the very limits of physical endurance, and consequently included in the above lists some patients who were not able to procure the comforts and attention necessary to the sick. Some cases also were included to which the physician was only brought that he might sign the death-certificate and so avoid the coroner's inquest. After making allowance for increase of mortality on these scores, I think it safe to assert that the best results obtained in private practice varied from 7 to 10 per cent. of mortality-rate.
DIAGNOSIS.—While there is no one symptom pathognomonic of yellow fever in every stage of the disease, its differential diagnosis is nearly always possible. The morbid action of its special poison produces phenomena sufficiently characteristic to prove its presence. The sudden attack, the slight cold stage, the frontal and lumbar pain, and the capillary congestion are important diagnostic symptoms.
Even in mild attacks this capillary blood-stasis is usually sufficient to alter the patient's countenance to such a degree as to attract attention. A great many different adjectives are used in description of the countenances of yellow-fever patients. While no one among them is constantly applicable, the presence of a changed facial expression should enlist the physician's attention and incite investigation. If this altered countenance be associated with watery or glistening injected eyes, the probability of yellow fever is increased.
The slow pulse which coexists with elevated temperature is a point of much diagnostic value. But it must be remembered that this symptom is not peculiar to yellow fever. I have noted this lack of correlation of pulse and temperature in several cases of dengue. It is also not infrequently found in ordinary cases of jaundice. The slow pulse of yellow fever must be attributable to the special action of the poison upon the nervous system. The heart's action may be slowed by influences exerted directly or through the retrograde effects of the delay of blood-currents in the capillary distribution.
Albuminous urine is a symptom of much diagnostic importance.