LETTEE OF TEAE'SMITTAL. 
Sir : I have the honor to transmit herewith a syllabus of the course 
in pathology and bacteriology given in this laboratory. 
This is the completion of the third year in which the course of 
instruction as outlined in the following pages has been given by the 
present director of the laboratory to the student- ofi&cers of the Service. 
Advantage has been taken of many practical points gained from actual 
experience both from the standpoint of the student and that of the 
instructor, so that the course as now outlined is believed to fairly cover 
the ground and to require few changes other than those due to advances 
in our knowledge upon the subjects treated. 
The object of the course is to thoroughly equip officers of the Service 
in the technique of pathology and bacteriology so as to fit them better 
for the hospital, quarantine, epidemic, and public-health work of the 
Service. Officers of the Service who have taken the prescribed course 
are thoroughly prepared to make the scientific diagnoses of plague, 
cholera, diphtheria, tetanus, tuberculosis, typhoid fever, anthrax, and 
other communicable diseases, as well as to carry on original investi- 
gations for themselves. 
The course as outlined requires about one year for its completion. The 
student- officer is required to work each subject until he has mastered it 
before going on to the next. Such delibei'ation permits a thoroughness 
which is not possible when work is hurried or limited to a short space 
of time. 
The exact sequence as given on the following pages is not strictly 
adhered to, because it is the desire of the director to make the course 
as practical as circumstances will permit. Therefore, the study of diph- 
theria is usually left until the fall of the year or winter, when practical 
experience may be had with the cases which usually occur in the Dis- 
trict. The studies upon vaccinia and smallpox are taken up in the 
winter, which time is more apt to offer material and cases. Malarial 
work is of course confined to the summer and fall seasons. In connection 
with the health department of the District, the work of diagnosing 
diphtheria from swabs and culture tubes and the administration of anti- 
toxin, both for prophylactic and curative purposes, is carried on by 
each student-officer. In connection with the studies upon vaccinia, a 
visit is always made to one of the large vaccine farms, which offers 
special advantages for observing the process of vaccinating the calves, 
obtaining the lymph and pulp, glycerinatihg the virus, and preparing 
