56 The Philippine Journal of Science 1920. 
be taken for the preservation of this important biologic product. 
In searching for data concerning the dried pulverized vaccine, 
we have to go back in the literature to 1881 to find the first note 
on the subject. Reissner in Darmstadt, and Frappoli in Italy, 
appear to have been the first ones to experiment with the dry- 
ing of vaccine virus. It was at that time that the preservation 
of vaccine virus for wide distribution and shipping was desirable; 
but the glycerinized vaccine virus, as introduced by Muller about 
the same time, became supreme, and was so satisfactory that 
no further attempts were made to dry the vaccine virus. As 
far as the Philippine Islands is concerned, we find a note on the 
“Preservation of vaccine virus” by E. H. Ruediger in the Bul- 
letin of the Manila Medical Society, August, 1910. 
In preparing dried vaccine naturally three requirements have 
to be fulfilled. First, the drying must take place as rapidly 
and as completely as possible, and without the application of 
artificial heat. Second, the preservation must be such as to 
keep the powder in absolutely dry condition; it must be kept 
away from light, particularly sunshine, and from heat. Third, 
the bacterial content of the dried vaccine must be considered ; 
in the absence of glycerine, which in the glycerinized vaccine 
acts not only as a preservative but also as a bactericide, the 
bacterial content in the dried vaccine will naturally be higher 
than in the glycerinized vaccine. 
EXPERIMENTS PROPER 
The vaccine was prepared in the following way: The pulp 
obtained by scraping a vaccinated animal was ground up in a 
sterile mortar, spread over a large surface under aseptic con- 
ditions and dried rapidly over a hygroscopic chemical in vacuum, 
ground up, perfectly dried, and kept in a desiccator at room 
temperature. Every week one monkey was vaccinated with a 
small portion of this powder and kept under observation in 
order to ascertain whether or not there was any difference in 
the development of the “take” in this monkey and that of another 
one, used as control, which had been inoculated at the same time 
but with fresh glycerinized vaccine. Up to date of writing, 
that is, four months from the time the vaccine was prepared 
(and it was kept at room temperature all the time), we have 
obtained in all inoculated animals first-class “takes” which could 
not be distinguished from the “take” in the control animal in- 
oculated with fresh vaccine. We cannot, therefore, at the pres- 
ent writing state definitely how long the dried and pulverized 
vaccine will keep. But, in view of the fact that the experi- 
