237 



had received the infection through the food or drink of which all had 

 partaken in common. 



Clinical History. — In different localities, in different epidemics or 

 groups of cases, and in different individuals, the symptoms of yellow fever 

 may present considerable departures from any given, standard. It will 

 not be difficult, however, to distribute the cases into one or other of the 

 three following classes, which it is most essential that every physician 

 should bear in mind in visiting a yellow fever locality. 



The three types or forms alluded to are : 



1. — The "acclimation fever", or "non-albuminurie yellow fever." 



2. — The "plain albuminuric yellow fever." 



3. — The "melano-albuminuric yellow fever." 



The line is drawn between the first and the second forms by the ab- 

 sence of albumin from the urine in the first, and its presence in the second. 

 The distinction between the second and the third forms is established by 

 the presence, in the "melano-albuminuric", of blood or "black vomit" in 

 the stomach or bowels, whereas in the "plain albuminuric", though haemor- 

 rhages may develop in other parts of the body, and vomiting or nausea 

 may be well marked, neither blood nor "black vomit" is ever present in 

 the stomach or bowels. 



Between three days and twenty-five days may elapse after exposure to 

 the yellow fever infection before the attack declares itself, vague prodromic 

 symptoms being sometimes experienced. The patient is then suddenly 

 seized with headache and fever (with or without a chill), the headache 

 principally occupying the front part of the head ; sensitiveness under the 

 eyebrows, often increased when the eyeballs are rolled upwards ; pain in 

 the loins and limbs, and general discomfort. There is general turgesence of 

 the capillary circulation; the countenance is flushed, the eyes injected 

 and watery ; the skin may be either dry or moist, sometimes even bedewed 

 with drops of perspiration. The stomach may not be affected except by 

 increased thirst and reluctance for food of every kind, or it may be irrit- 

 able, throwing up undigested food or bile, rejecting everything that is 

 taken, and sensitive to pressure over the epigastrium. This irritability of 

 the first period generally subsides in the course of the first or second day. 



The symptoms are rapidly developed, and the acme of the fever is 

 generally reached during the first or second day, with temperatures 

 which may not exceed 38° or 39° C, but often rise as high as 40° C. The 

 pulse is rapid and full at the onset, but after the acme of temperature it 

 slackens, and becomes, as a rule, slower than appears consistent with the 

 fever heat. In nervous, excitable persons, however, the pulse may continue 

 rapid. The urine is generally diminished in quantity, and continues so 

 until the decline of the attack. 



The above symptoms are common to the three forms of the disease, 

 though all may not be present nor equally marked. Indeed, excepting the 



