Black took a position as assistant to the established chemist Carlington Marston in his Smith Street pharmacy and eventually took over the business. With two sons following him into pharmaceutical studies, the business continued into the 1930s as J.S. Black and Sons, and the 1867 building still exists.

Black studied pharmacy in Glasgow, arrived in Melbourne 1852, spent some years at the diggings with occasional returns to pharmacy when times were bad, then finally joined Marston in 1873. After the Marstons moved house to Kew, Black and his family lived above the shop. He became a member of the Pharmaceutical Society in 1883. In the early 1890s Marston retired but retained ownership of the shop when Black took over the business. From early 1893 the following advertisement appeared in the Mercury and Weekly Courier:

J S Black, Pharmaceutical & Family Chemist, 198 Smith St has the honor to announce that he has succeeded to the Old Established business lately carried on under the proprietorship of C Marston, and where he has been assistant for many years. He trusts that his special experiences will be a sufficient guarantee of his ability and skill, and by giving personal attention to business he may at all times command the confidence and support of the public.

His eldest son John William Carden Black (1873-1939) was born in Sandhurst, qualified as a pharmacist in 1894, and joined his father in his business at 198 Smith Street. He married Agnes Dorman in 1899 and the young couple also lived above the shop.  In 1901 Black senior and his wife retired to Seville.  According to his obituary in 1913, Black was highly esteemed by all who knew him, was of a courteous and kindly-dispositioned nature and took a great interest in the welfare of pharmacy.

At this time John junior and Agnes moved to Powlett Street East Melbourne where they were joined by Mrs Black senior. She was one of the earliest members of the Australian Church and its founder, Rev Dr Strong, officiated at her funeral in 1916. The second son, also a pharmacist, later qualified as a doctor and moved to Horsham

The Argus, Mercury, Fitzroy City News, Australasian Journal of Pharmacy April 1913 p. 126

Obituary with photo

196-198 Smith St