58 
Table 2 .—Period of incubation in yellow fever, etc— Continued. 
[Reed and Carroll: “The etiology of yellow fever; a supplemental note,”Am. Med.,Feb.22,1902.] 
Case No.— 
Inoculated. 
Attack. 
Incubation. 
6 (7) .. 
Oct. 15, 11 a. m_ 
Oct. 19, 3 p. m_ 
Oct. 19, noon.. _ 
4 days 4 hours. 
4 days 1 hour. 
7(8)-- 
Oct. 15, 11.05 a. m_ 
Cases 6 and 7 were inoculated subcutaneously with 3 cc. of an equal volume of water and 
serum filtered through a Berkefeld filter. 
[Marchoux, Salimbeni, and Simond: “La flevre jaune,” Rapport de la mission frangaise, Insti¬ 
tute Pasteur, Annales, November, 1903.] 
Case No.— 
Incubation. 
8 ( 1 ) 
9 (3) 
10(4) 
11 (?) - 
12 (8) . 
13(13) 
14(15) 
1 cc. serum..... 
5 cc. serum heated to 55° for ten minutes; five days later, 10 cc. 
heated to 55° for ten minutes; seven days later, 1 cc. blood. 
This was a “remarkably benign case,” and as the man had 
been injected previously with heated yellow fever serum, 
the immunity produced probably explains the long period 
of incubation as well as the mildness of the Attack. 
5 cc. serum heated to 55° for twenty minutes; seven days 
later, 10 cc. serum heated to 55° for ten minutes; eight days 
later, 1 cc. serum heated to 55° for five minutes. Then 1 cc. 
serum. 
The same explanation for this unusually long period of incu¬ 
bation as above, especially as a parallel case similarly 
treated showed an immunity. 
1 cc. serum filtered through a Chamber land F filter_ 
_do________ _ 
0.1 cc. (1 drop) of serum___ 
5 cc. blood, 5 days old....... 
5 days 5 hours. 
12 days 12 hours. 
8 days 5 hours. 
5 days 18 hours. 
12 days 18 hours. 
4 days 18 hours. 
2 days 21 hours. 
[Francis and Beyer.] 
Case No.— 
Inoculated. 
Attack. 
Incubation. 
15 (2) a _ 
16 (3) b 
Sept. 15, 4 p. m... 
do 
Sept. 17, (?) a. m_ 
do 
1 day, 15hours (about). 
Do. 
17 (4) c._ 
.do. . 
Sept. 17, 9 a. m_ 
1 day, i7 hours. 
«Intravenous injection of 1.75 cc. serum diluted with an equal volume of salt solution and 
filtered through a Chamberland B filter. 
b Intravenous injection of 2.5 cc. serum diluted with an equal volume of salt solution and 
filtered through a Chamberland B filter. 
c Intravenous injection of 2.5 cc. serum diluted with an equal volume of salt solution and 
filtered through a Chamberland B filter. 
It will be noted from these IT cases that the period of incubation of 
yellow fever produced by the inoculation of blood or blood serum is 
not so constant a factor as in Table 1, in which the disease was in¬ 
duced by the bites of mosquitoes. 
The shortest time in this table is one day fifteen hours, and the long¬ 
est twelve days eighteen hours. 
Surg. H. R. Carter, Public Health and Marine-Hospital Service, 
has given special attention to this phase of the subject, and we are in¬ 
debted to him for valuable suggestions. 
THE FILTRATION OF YELLOW-FEVER BLOOD. 
Reed and Carroll /Am. Med., Feb. 22, 1902) were the first to filter 
yellow-fever blood and prove the infectiousness of the filtrate. They 
passed it through a Berkefeld filter, which on testing held back the 
Staphylococcus pyogenes aureus. 
