THE TEXAS ACADEMY OF SCIENCE 
[annual address by the president.] 
SOME ADVANCES MADE IN OUR KNOWLEDGE OF 
IMMUNITY AND PROTECTIVE INOCULATION. 
HENRY WINSTON HARPER, 
University of Texas. 
In grateful acknowledgment of the honor done me hy the fellows 
and members of the Texas Academy of Science, it is my purpose 
this evening to bring before you “Some Advances Made in Our 
Knowledge of Immunity and Protective Inoculation.” 
“When we search the history of the development of scientific 
truth we learn that no new fact or achievement ever stands by 
itself, no new discovery ever leaps forth in perfect panoply, as 
Minerva did from the brow of Jove. 
“Absolute originality does not exist, and a new discovery is 
largely the product of what has gone before. 
“ ‘We may be confident that each forward step is not ordered by 
one individual alone, but is also the outcome in a large measure 
of the labors of others. The history of scientific effort tells us that 
the past is not something to look back upon with regret — some- 
thing lost, never to be recalled — but rather as an abiding influence 
helping us to accomplish yet greater successes / 1 * 1 
“Again and again we may read in the words of some half-for- 
gotten worthy the outlines of an idea which has shone forth in later 
days as an acknowledged truth .” — Sir William MacCormac . 1 
The fact that persons once afflicted with smallpox rarely expe- 
rienced a second attack of that disease when repeatedly exposed to 
it, was not only early observed, but made a matter of record by the 
Chinese long before the beginning of the Christian era. That the 
disease was contagious had long been a matter of common expe- 
rience, and the means of protection against its ravages early became 
an interesting subject for investigation. 
The Chinese observed that when the dried and pulverized mate- 
