Happy birthday to Louis Pasteur, French chemist and microbiologist who is well known for his discoveries of the principles of vaccination, microbial fermentation and pasteurization. He is remembered for his remarkable breakthroughs in the causes and prevention of diseases, and his discoveries have saved countless lives ever since. Pasteur reduced mortality from puerperal fever, and created the first vaccines for rabies and anthrax. His medical discoveries provided direct support for the germ theory of disease and its application in clinical medicine. Pasteur is best known to the general public for his invention of the technique of treating milk and wine to stop bacterial contamination, a process now called pasteurization. He is regarded as one of the three main founders of bacteriology, together with Ferdinand Cohn and Robert Koch, and is popularly known as the “father of microbiology.”
Pasteur also made significant discoveries in chemistry, most notably on the molecular basis for the asymmetry of certain crystals and racemization. He was the Director of the Pasteur Institute, established in 1887, until his death, and his body lies beneath the institute in a vault covered in depictions of his accomplishments in Byzantine mosaics.
Louis Pasteur was born on December 27, 1822, in Dole, Jura, France, to a poor tanner. He was the third child of Jean-Joseph Pasteur and Jeanne-Etiennette Roqui. In 1827, the family moved to Arbois, where he entered primary school in 1831. Pasteur was an average student in his early years, and not particularly academic, as his interests were fishing and sketching. His pastels and portraits of his parents and friends, made when he was 15, were later kept in the museum of the Pasteur Institute in Paris. In 1838, he left for Paris to join the Institution Barbet, but became homesick and returned in November. In 1839, he entered the Collège Royal de Besançon and earned his BA degree in 1840. Pasteur continued there for a BSc degree with special mathematics but failed in 1841. He succeeded in 1842 from Dijon with a poor grade in chemistry. After one failed attempt for the entrance test for the École Normale Supérieure in Paris in 1842, he succeeded in 1844, and received his medical license the next year. In 1846, he was appointed professor of physics at the Collège de Tournon at Ardèche, but Antoine Jérome Balard (one of the discoverers of the element bromine) wanted him back at the École Normale Supérieure as a graduate assistant (préparateur) for chemistry courses. Pasteur joined Balard and simultaneously started his research in crystallography and in 1847, he submitted his two theses, one in chemistry and the other in physics. After serving briefly as professor of physics at the Dijon Lycée in 1848, he became professor of chemistry at the University of Strasbourg, where he met and courted Marie Laurent, daughter of the university’s rector in 1849. They were married on May 29, 1849, and together had five children, only two of whom survived to adulthood; the other three died of typhoid. These personal tragedies were his motivations for curing infectious diseases.
Dulce de Leche
So . . . let’s boil some milk. If you boil it slowly and constantly you will end up with a thick caramelized treat known in Argentina as dulce de leche. It takes about 36 hours, though. I’ve done it once. My mum made it the quicker way. Take a can of sweetened condensed milk. Pierce a couple of holes in the can (my mum would tell you what happens if you don’t). Place the can in boiling water and let it sit until the milk has thoroughly caramelized (about 3 hours). Spread it on toast, eat it with ice cream . . . it is the taste of Argentina.