Born in Mulhouse, Alsace 1855, died in Geneva 1928; anarchist, freethinker and freemason; became involved in socialist activities already at the age of fifteen in Mulhouse; member of the local section of the International Working Men's Association (IWMA); also active in the Ligue d'Alsace and distributor of their clandestine publications; went to Switzerland about 1874; became anarchist in the mid-70s; delegate to the Berne Congress of the 'antiauthoritarian' International in 1876; participated in the famous Red Flag demonstration in Berne, March 1877, where he is said to have saved the life of the Russian revolutionary Z. Ralli; travelling widely and freely as salesman and representative of a leading Swiss cigar and cigarette manufacturer, he became one of the most successful distributors and smugglers of forbidden socialist and anarchist publications such as L'Avant-Garde, Le Révolté, Freiheit and Der Sozialdemokrat; contributed to many French, Italian and German anarchist periodicals, mostly anonymously or under the pseudonym Jeanquimarche; friend of many leading anarchists, including Luigi Galleani, Peter Kropotkin, Errico Malatesta and Max Nettlau, many of whom he supported financially when in need; he is also said to have formed one of the largest collections of anarchist and freethinker publications, rivalling that of Max Nettlau; much of it was sold in the early 1920s to the Frankfurt Institut für Sozialforschung, and the bulk of the remainder later incorporated into the collections of the IISH.

Papers donated to the IISH by J. Gross-Fulpius in 1938, see Annual Report IISH 1938, p. 17; with an accrual in 1939, see Annual Report IISH 1939, p. 31.

Correspondence mainly with anarchists; some manuscripts by Gross and others; photocopies of letters from Max Nettlau to Jacques Gross on Ernest Coeurderoy and some other documents on Coeurderoy; photocopies of letters from Jacques Gross to Ettore Molinari and others 1873-1927.

List made by Tiny de Boer in 2006

Part of his papers at the Centre International de Recherches sur l'Anarchisme (CIRA), Geneva.