Magnesia House

Magnesia House comprises a late 18th-century house, possibly a remodelling of a pair of houses built in 1733, and a small building constructed in 1780–81 known as the Committee Room, now named the Counting House. The property was altered and extended in the 20th century, probably during the inter-war period, and again in 1982–85, forming a single office premises.

Plan

The southern portion, originally a house of two storeys plus basement, was raised to three storeys plus attic in the 20th century. It faces east into Playhouse Yard and abuts Apothecaries Hall to the west; its north elevation faces the Apothecaries' Hall yard. The northern part, the Counting House, was originally one storey high but was raised to four storeys in 1982–85. The ground floor is linked to the Counting House by a doorway. Above ground floor level, the buildings are conjoined to form one large room.

Exterior

The front (east) elevation comprises three bays in two distinct parts demarcated by a straight joint in the brickwork. The two-bay house to the south is built in brown brick laid in Flemish bond. Areas of brickwork have been repaired, and the third floor is in red brick. The entrance is in the right-hand bay and has a pedimented doorcase with scrolled brackets and panelled reveals. The ground floor has a pair of blind oculi flanking the door and window. The south return into Playhouse Yard is curved and is enclosed at ground floor level by a canted wall enclosing a yard, now roofed over. The first-floor window appears to have been lowered to form an entrance or loading bay. The single-bay northern section is also built in brown brick, with red brick at upper levels and a pitched roof. The ground floor is blind. All windows are multi-paned sashes, many reinstated in the 20th century.

The house's rear (north) elevation has been partly obscured by the three-storey 1980s extension above the Counting House. The brickwork is 18th-century at lower levels and has a plat band between the ground and first floor. The ground floor has a tripartite sash window. The first-floor window opening has been re-formed. Windows are 20th-century replacements and have exposed sash boxes in the early 18th-century style. The Counting House, now the ground floor of the 1980s extension, has a single sash window to the bowed west elevation and two on the north, one of which has been modified to form a door. A double-faced brass clock is mounted on the north wall. Above this, the 1980s extension is built in rendered blockwork, bowed on the west side to follow the profile of the Counting House, while the north elevation is jettied over the ground floor, supported on pillars, and surmounted by a gable.

Interior

The interior of the 18th-century house has been radically altered and retains no visible features of interest. The Counting House is the only interior with special interest. It has full-height late 18th-century panelling with moulded cornices, incorporating shelves. The doorway to the right of the chimneybreast was relocated from the left-hand side in the 1980s. The vaulted basement is accessed by stone steps from the yard, and also by a stair inserted in the Counting House.

History

The Society of Apothecaries was incorporated as a City Livery Company by royal charter from James I in 1617, and in 1632 acquired Cobham Hall, the former guest house of the Dominican Priory of the Black Friars. This was destroyed in the Great Fire of London, and the new Apothecaries' Hall, which stands today, was built in 1666–72. From 1672, the Society manufactured and sold medicinal and pharmaceutical products, a function which continued until 1922; its 'Elaboratory' for the first ever large-scale manufacture of drugs was located in the basement of the Great Hall. The business was operated as a joint stock venture under the 'Proprietors of the Laboratory Stock'. A second company, the Navy Stock, was set up in 1703 with a monopoly on the supply of drugs to the Navy, occupying premises to the south and west of the Hall. These were rebuilt in 1780–81 and now form the south-west return of the Hall complex. In 1822 the two Stock companies were merged into the United Stock, and from 1881 a committee managed the pharmaceutical trade.

The development of the land to the east of the Hall on which Magnesia House stands began around 1667 when the Society acquired the site of the cloister, part of the estate of Gideon Delaune, former Master and benefactor of the Society. A row of four dwellings and shops was built in the early 1670s and a garden for the Society created to the north of this. A dwelling described as 'old' is shown on the site of Magnesia House on an early 18th-century plan. It had fallen into a ruinous state by 1732, and in December of that year Francis Hatt, carpenter, took a 72-year lease of the site on the understanding that he would replace it with one or more brick messuages at a cost of at least £200 by 24 June 1733. In 1780–81, the row of 17th-century houses, which stood to the north-east of the 1733 houses, was replaced by a two-storey chemical laboratory range for the Laboratory Stock; a further range was attached to this on the north-east side along Church Court. The Committee Room, a single-storey building with a bow front facing west, was attached to the west end of the laboratory range, abutting part of the houses' north elevation.

The date of the rebuilding of the 1733 houses as a single dwelling is unclear, but it seems to have taken place after the construction of the laboratory and Committee Room. An unsubstantiated date of 1792 is suggested, while the original 72-year lease would have expired in 1804, although the rebuilding may have taken place before that date. Plans from the 1732 lease, Roque's map (1746), and plans from a lease of 25 March 1778 showing two separate dwellings as 'houses on lease to Mr Hagan' all show that the buildings had a canted south-eastern return, which is consistent with the property boundary that exists today, but not with the distinctive curved elevation of the present building. Moreover, a series of leases of 1786 itemises 'two houses in Glasshouse Yard adjoining the Hall and Laboratory' as leased to the Navy Stock, while the Committee Room 'with stone steps down to the cellar' is leased to the Laboratory Stock. The lease plans of 1732 and 1778 show that the southern house had a cramped wedge plan, one room deep with a tiny yard behind; the northern one was larger and two rooms deep. The laboratory ranges to the east were demolished in the inter-war period, and the site is now occupied by Nestor House.

The manufacture of magnesium compounds was an important component of the pharmaceutical industry, and the laboratory ranges of 1781–82 included a magnesia laboratory. It is unclear whether Magnesia House itself was ever used for this purpose, although it appears to have fallen out of domestic use by 1886 when an insurance plan labels the ground floor as the 'Magnesia Room', and shows it as interlinked with the Counting House, labelled as 'Office'. The doorway has been relocated from the left-hand to the right-hand side of the fireplace.

Magnesia House is designated at Grade II for its architectural interest as a late 18th-century house, possibly a remodelling of an earlier pair of houses of 1733, and a former committee room serving the pharmaceutical laboratories which stood to the east (now demolished), retaining good-quality panelling with built-in shelves. It holds historic interest for its close associations with the Apothecaries Hall and its role in the production of pharmaceuticals until the 20th century, and has group value with the Grade I listed Apothecaries' Hall complex.