70 Transactions Texas Academy of Science, — 1908-1909. 
home early in April, 1861, between sunup and sundown. Reaching 
Louisville, Ky., he enlisted in Company D, First Kentucky Infantry, 
and at Harper’s Ferry was sworn into the Confederate Army to serve 
for twelve months. He remained in service, however, until army sur- 
rendered in 1865, serving at various times under Johnston, Jackson, 
Morgan and Forrest. 
“Being still rebellious and unreconstructed, McLaughlin and A. H. 
Cross, an army comrade, started for South America. But on reaching 
Texas, McLaughlin met Miss Tabitha Bird Moore, who later became 
his wife, and decided to take up medicine as a profession. He at 
once entered into its practice with Dr. Sam D. McLeary, near Colum- 
bus, Texas. Working diligently, the following spring, (1867), after 
completing the prescribed course of study, he graduated from Medi- 
cal Department of the University of Louisiana. 
“His marriage was solemnized in September of the same year, and 
with his devoted wife he located in Fayette county for the practice 
of his profession, where he remained until 1869, when he removed to 
Austin.” 
Dr. McLaughlin practiced in Austin thirty-two years, when he was 
called to the chair of Medicine in the Medical Department of the 
University of Texas. This chair he filled with distinction eight years, 
when he resigned and returned to Austin. Dr. McLaughlin was 
President of the Texas State Medical Association in 1894, a regent 
of the University of Texas from 1907 until his death, and President 
of the Texas Academy of Science at the time of his death. 
As a mature man the greater part of Dr. McLaughlin’s energies 
was devoted to the practice of his profession. Of that I shall speak 
later, but the attraction of the scientific side was very strong, and 
soon led him to devote much time and thought to the scientific work 
he liked best. Very early in the medical career his thoughts were 
directed toward an explanation of drug action. This led to investi- 
gations which resulted in his well-known wave-interference theory of 
catalysis, and catalytic theory of immunization, which he worked upon 
to his last days. His views on the different problems constitute in 
Jhe judgment of the competent, a noteworthy contribution to scien- 
tific theory. 
Possibly even more valuable was the work he did during the epi- 
demic of dengue in 1885, which resulted in his discovery of the bacil- 
lus of that fever. When we remember that this work was done, not 
in a laboratory equipped with all modem appliances, which do so 
much to ease the work of the student, and so little to develop his re- 
sourcefulness, but in a room at his residence, surrounded by the most 
