Utah, British Columbia, California, and the Mexican border regions 
of Arizona. In the early years of his practice in St. Louis, however, 
he had to spend a great deal of time attending patients. And his hard 
work paid off, as he eventually gained the reputation as the communi- 
ty’s most prestigious obstetrician. 
Although his professional duties kept him busy, Engelmann con- 
tinued to compile scientific information and collect specimens in St. 
Louis. Throughout his life he made detailed daily meteorological readings 
and published summaries of his findings. Engelmann’s meteorological 
commentaries constituted more than a hobby: they were directly ap- 
plicable to important scientific work undertaken by explorers and scien- 
tists in the Midwest. The French geographer and astronomer Jean 
Nicollet found Engelmann’s data, along with those accumulated by the 
Jesuit Fathers of St. Louis University, useful in preparing for his survey 
of the Upper Mississippi River Valley.® 
In addition to busying himself with watching and recording the 
weather, Engelmann continued to personally collect plants when he 
could. He also traded for or bought specimens from other collectors, 
which he in turn sold or exchanged with museums and naturalists in 
the United States and Europe. He also procured specimens by affiliating 
himself with exploring parties heading for the West, including those 
of John C. Fremont and Josiah Gregg. Engelmann gave advice and 
checked the accuracy of the explorers’ scientific instruments, and they 
repaid him by gathering botanical and geological specimens. Engelmann 
frequently managed to get his own collectors appointed to trading and 
military expeditions. These individuals were university-trained St. Louis 
Germans hand-picked and instructed by Engelmann. 
In the course of his collecting, Engelmann made many contacts 
with scientists and science societies all over the country and the world. 
He had strong ties with the Academy of Natural Sciences of Philadelphia 
and corresponded with a variety of prominent scientists, including the 
pioneering naturalist Jacob Lindheimer, who worked in Texas, and the 
distinguished Asa Gray of Harvard. Gray frequently received botanical 
specimens from Engelmann and, in return, helped the St. Louis amateur 
scientist raise funds for collecting expeditions. 
Engelmann soon gained a national reputation, which sprouted from 
his collecting and grew as a result of scholarly accomplishments. He 
was the first to point out that American grapes were immune to the 
phylloxera that ravaged European vineyards. In 1842 he wrote a paper 
on American as glories, which according to a later nineteenth 
century appraisal, ‘‘caused a true sensation in botanical circles.’’ In 
1852 he published in the American Journal of Science the first scien- 
tific description of the impressive saguaro cactus. He subsequently 
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