Art. 35 OR; merchant woman and personal enforceability of a married woman; the legally required consent of the husband must be shown, expressly or by sufficiently established implied authorization. Isolated business transactions with a single creditor do not suffice to prove autonomous commercial activity addressed to a wider clientele. The Federal Court is bound by non-arbitrary factual findings of the cantonal supervisory authority; where the record supports the view that the husband conducts the business and the wife merely performs ancillary correspondence, merchant-woman status is excluded (consid. 2).