<b>1870 * - 1883 Liège, Rue Bertholet, 7</b> Nicolas Renier Léon ° 12.5.1845; + 13.1.1915. Chemical engineer. Director of the department for chemistry and physics products and equipment at Jonniaux in 1867, he sold photographic cameras and chemicals from 1870. In 1879, Recorded as a chemist at his wedding in Liège on 24.6.1871. Laoureux invented a printing process using ferric oxalate, which was commercialised by the Jonniaux firm in 1882. Founder member of the ABP, he was also one of its instigators. <b>1884 - 1914 > Liège, Rue de la Cathédrale, 10<00-04>, 12<05>, 56<11-14> or 60<05-14></b> Predecessor: Jonniaux Charles (Père) Photographic supplies. At this address from 1884 but still living in Rue Bertholet in 1898. About 1890, "Henkart & Laoureux". Photographs of mills in the Amblève valley. Views of Switzerland. He organised the first public slide show held by the Liège section of the ABP on 18.4.1889. Vice-president from 1904 until 1907. He organised a photographic congress in Liège during the Universal Exhibition in 1905 and was a member of the jury for Group 12 'Photography'. Member of the "Association belge des chimistes" in 1898. At no. 56, "Léon Laoureux & Cie, successor to C.B. Jonniaux & Frères. Firm founded in 1810. Equipment for chemistry, bacteriology, physics and photography" (advertisement, 5.12.1911). Laoureux was recorded as a chemist domiciled in Liège and resident at Rouvreux on his death certificate, which was witnessed by his nephew Georges (see that name). <b>1907 - 1914 Liège, Boulevard d'Avroy, 41</b> Recorded in the ABP membership lists, this is possibly a private address. ABP listed previously: Quai de la Boverie, 25.