Amanda Theodosia Jones/Mary Engle Pennington
VACUUM CANNING
After several largely unsuccessful careers as a feminist educator, psy-
chic spiritualist, and poet, Amanda Theodosia Jones hit pay dirt with a
prosaic glass jar. In 1872 Miss Jones conceived of a vacuum process
for preserving food. Her "Jones exhauster" (the name would never
catch on) was awarded Patents #139.547. * 139.580, and #140,247
for a system in which food was placed in a container, the air drained
out through a series of valves, and hot (100 to 120¡F) liquid added to
the container to complete the seal.
Jones's vacuum-canning process revolutionized food preservation, a
cause of great concern to a nation that was rapidly changing from
rural to urban. Her invention allowed, for the first time, fresh food to
be stored in quantity without having to cook all the flavor out of it.
Everything from lunch meat to tapioca pudding was soon being man-
ufactured with Jones's processÑmuch of it at her female-owned and
operated U.S. Women's Pure Food Vacuum Preserving Company in
Chicago.
Mary Engle Pennington was born the year that Jones filed her first
vacuum-canning patents. Twenty-five years later Pennington would
again revolutionize the food industry with her patents for refriger-
ation.
Unlike her predecessor, Pennington was quite sure she wanted tii
be a scientist from a very early ageÑduring an era that looked upon
men scientists as at best an oddity and at worst an abomination
gainst God. Completing her bachelor of science requirements at the
L diversity of Pennsylvania, Pennington was refused a degree because
of her gender. Undaunted, she continued her postgraduate studies
Èith such stellar performance that she eventually shamed the faculty
into awarding her a Ph.D. She may be the only person refused a bach-
rior's degree but awarded a doctorate from the same university.
Unable to find employment (that gender problem again), she opened
her own business, the Philadelphia Clinical Laboratory, specializing in
bacteriology. Her research into food spoilage brought her to the atten-
e 'n of the chief chemist of the U.S. Department of Agriculture, and he
tiiew that her talents would be invaluable at the government level. He
also knew that the department would never hire a woman.
So "M. E. Pennington" took and passed the civil service exam, and
MOD "Mr. Pennington" was welcomed into the U.S. Food Research
Laboratory, where he ... ah, she specialized in studying the spoilage
iiiiit foods. Even today spoilage is a matter of grave concern; think of the
¥pcent deaths due to E. coli contamination. At the beginning of the
Ñwntieth century, when Pennington set up shop, bacteria felled thou-
xoDcLs of people annually, especially during the summer in large cities.
Cold temperature kills most bacteria. But the problem with early
imrfrigeration systems was that as the temperature dropped inside the
Urood locker, humidity was lost and the food dried out. Increase
URumdity and the food spoiled. There was no point making the food
fr ; "teria-free if no one was inclined to eat it.
''¥nnington solved the problem of humidity control. Her innova-
¥i :-- in refrigeration were so vital that during World War I she was
ÑEarded a Notable Service Medal by President Herbert Hoover.