20 The Philippine Journal of Science isis 
ence to the action of vaccines are many, and opinion is far from 
unanimous. The claims made by some, that the curative effect 
of vaccines is due to their specific action, have been held to be 
untenable, so that many look upon the question as still unsettled. 
It is my intention to make the present paper the basis of my 
contribution to this much-disputed question, although conscious 
of the fact that it requires some temerity to enter a field already 
occupied by so many distinguished American and European 
writers. I hope, however, to set forth some facts in connection 
with these methods of treatment and then to present the con- 
clusions reached through my observations. 
PRESENTATION OF THE CLINICAL CASES 
Period of observation. — The present investigation covers a 
period of seven months, beginning August, 1,917, and extending 
to February, 1918. During that time there were admitted to 
the medical department in the Philippine General Hospital nine- 
ty-eight cases of typhoid fever, all Filipinos. Both sexes are 
represented in the series. The minimum age was 14 years. 
Another series of twenty cases of typhoid fever has not 
been included with these ninety-eight cases for the reason that 
some were in a dying condition on admission and, therefore, 
short-lived in the hospital ; and others were admitted in a con- 
valescent state, in which they showed marked defervescence. In 
connection with these convalescent cases it was felt that the 
effects of the treatment under consideration in this paper might 
lead to erroneously favorable interpretations. 
Source of material. — The source of the cases studied was the 
district of Manila. Relatively few cases came from Rizal, Ca- 
vite, Bulacan, and Laguna Provinces. 
Type of epidemic. — Many of the patients on admission showed 
marked toxaemia, frequently associated with pneumonic, cardiac, 
or renal complications; while other cases were admitted in a 
condition of collapse, either with intestinal perforation or acute 
intestinal haemorrhage. It can be fairly stated, then, that we 
were dealing with a severe type of epidemic. It should be fur- 
ther stated that, with very few exceptions, these typhoid cases 
belonged to the laboring class of the community, whose hygiene 
and dietary were very deficient. Upon falling ill many of them 
remained in their homes for a number of days without any med- 
ical attendance, and only applied to the hospital for admission 
when their condition had become very serious. 
In these ninety-eight cases males predominated over females. 
The sex incidence is shown in Table I. 
