Biography of David (Didier) Roth (1810-1885)

The Jewish David Roth was born in 1800 in the Cassovia town in Austro-Hungarian Empire (now Košice in Slovakia). At this time, anti-semitism was particularly strong in the Hapsburg monarchy (e. g. Jews had to live outside the town), but the Roth family seemed to benefit from special permissions. His father died when he was only 10. His mother, who had a private income, stayed in town and worked at a kosher restaurant. The young Roth left Cassovia to study medicine in Vienna. The medical school in Vienna was highly conservative and homeopathic medicine, commended by Samuel Hahnemann, was really not the flavor of the day. It was not authorized until nearly 1829. It was probably at that period that David Roth stood up for this new medical approach. In 1830, a cholera epidemic struck Austria. There was panic in the towns. The Jews were accused of poisoning the wells. In the circumstances, one can understand why Roth, a young medical graduate, would decide to leave Austria for a somewhat gentler country.

So the young doctor emigrated to Paris, France, where he became as a well-known doctor of homeopathic medicine (under the name Didier Roth) for a rich Parisian clientele for more than 30 years. During the 1840s, he was private physician to the Austrian Embassy in Paris and Baron Rothschild.

In France Roth published several medicine books—in 1832, he published his Health Instructions against Cholera Morbus. He said he had cared for a large number of patients there. Between 1836 and 1840, he published Homeopathic Clinic, an enormous compendium in nine volumes recording nearly 5000 clinical observations. His History of irresistible musculature or normal chorea earned him a medal from the Académie Nationale de Médecine in 1850. His talents for translation (English/French/German) made him an unavoidable publisher of homeopathic thinking in Europe.

It is unknown what was the primary reason for the reputable doctor to leave the homeopathic circle to invent calculating machines. Most probably the French National Exposition (Exposition Nationale) of 1844. Between 1840 and 1844, Roth registered 6 patents—totaling 72 pages. At the Exposition Nationale in 1844, he presented several calculating machines as well as gas meters. He was awarded a bronze medal for his inventions.

Let's see an extract from "Report of the Exposition Nationale of 1844":
"Dr Roth presented arithmetic machines which he had invented for the jury to examine; some intended only for the two first rules, the others, more complete, working multiplication and division as well; he also presented meters for steam machines and other similar devices. None of these machines is new in its intended purpose; but Dr Roth has solved these various problems by simple means worthy of interest. The jury awarded Dr Roth a bronze medal."

Another famous inventor, who also presented several calculating machines was an outstanding figure in the industry of mechanical calculators—Thomas de Colmar. He only received a medal of encouragement. Roth certainly has been acquainted with the machines of de Colmar, as can be seen by the descriptive memo, serving as as a prelude to his second patent of 18th of June, 1841.

It seems that after the remarkable primary success of his calculating devices, Roth gave up mechanics and continued practicing homeopathic medicine for a rich clientele in Paris.

Dr Roth was very passionate about art, and managed to build up a very beautiful collection of old engravings, notably by Dürer, which are now kept in the Bibliothèque Nationale in Paris.

Roth was married for Nathalie Sassary, but had no children.

With age his sight deteriorated and at the end of his life Roth became completely blind. This extraordinary man died in 1885 and was burried in the Montmartre cemetery in Paris.