Kempthorne Prosser

Kempthorne Prosser was a major New Zealand drug, chemical and fertiliser company founded in Dunedin in 1870 by chemists Thomas Whitelock Kempthorne and Evan Prosser. Its formal corporate identity developed in 1879, when the partnership became a limited-liability company associated with the New Zealand Drug Company. Although the business began as a pharmaceutical wholesaler and manufacturer, its most consequential industrial contribution was the creation of a domestic superphosphate fertiliser industry. The company established its first major chemical works at Burnside in Dunedin in 1881. There it became the first New Zealand producer to combine sulphuric acid and bone dust to make superphosphate, an important fertiliser for the country’s agricultural and pastoral economy. Kempthorne Prosser subsequently built or operated large works at Westfield in Auckland, Hornby in Christchurch and Aramoho in Wanganui. For decades, the initials “K.P.” were closely associated with fertiliser manufacture in New Zealand, and the company held a dominant position in the fertiliser market until competition expanded during the early twentieth century. Pharmaceutical and consumer products remained part of the business. Kempthorne Prosser supplied chemists and hospitals around New Zealand and produced medicines, chemical preparations, flavouring essences and other drugstore goods. Products associated with the brand included K.P. Lifesalt, a mineral-salt drink marketed from the late 1920s into at least the 1940s, and a range of flavouring essences. Its industrial range included branded fertilisers such as KP Rockland and Westfield Manures. The company also published practical agricultural material, including editions of Profitable Fertilising in New Zealand and the KP Fertiliser Handbook. Kempthorne Prosser’s physical presence extended well beyond its factories. Its early premises and laboratory were located on Stafford Street in Dunedin, while the company maintained offices, warehouses and commercial properties in Auckland, Wellington and Christchurch. Several former industrial buildings survived into later periods, although others were demolished or substantially redeveloped. The Burnside works closed in 1962 and was sold to Dominion Fertiliser; the Westfield, Hornby and Wanganui sites later became associated with Ravensdown’s fertiliser operations. By the 1970s, New Zealand agricultural producers increasingly sought greater control over fertiliser supply. With financial support from Brierley Investments and producer-board funds, the Ravensdown Fertiliser Co-operative acquired Kempthorne Prosser in 1978. The transaction ended Kempthorne Prosser’s independent operation and removed its branded corporate identity from the market. Its industrial legacy nevertheless continued through the fertiliser facilities and cooperative business that followed it.

Thomas Whitelock Kempthorne arrived in Dunedin in 1863 after working in Melbourne’s wholesale drug trade. Following an unsuccessful earlier partnership, he joined Evan Prosser, a Welsh chemist who had operated in Hokitika and later moved to Dunedin. Their chemist business, formed in 1870, grew into Kempthorne Prosser & Co. The firm’s limited-liability structure was established in 1879, when it was linked with the New Zealand Drug Company and capitalised at £200,000. The company initially concentrated on pharmaceutical commerce and manufacturing. Its premises on Stafford Street, Dunedin, included offices and later a laboratory, and its products were distributed through chemists and hospitals across New Zealand. The business also developed a broad chemical portfolio, ranging from medicines and household preparations to flavourings and industrial materials. Its decisive expansion came in 1881. In response to a government incentive for domestic sulphuric-acid production, Kempthorne Prosser built the Burnside Chemical Works in Dunedin. The plant became the first in New Zealand to manufacture superphosphate by combining sulphuric acid with bone dust. This innovation helped establish a local fertiliser industry and tied the company to the country’s rapidly developing agricultural economy. Further chemical works opened at Westfield in Auckland in 1887, Hornby in Christchurch in 1922 and Aramoho in Wanganui in 1926. Kempthorne Prosser dominated New Zealand’s fertiliser trade for much of the period before about 1920, and remained an important producer for almost a century. Its agricultural products included KP Rockland and Westfield Manures, while its publications instructed farmers in fertiliser use. The company also retained a pharmaceutical and consumer-products identity, notably through K.P. Lifesalt and flavouring essences. The company’s founders followed different paths. Kempthorne remained managing director until retiring in 1904 and died in Dunedin in 1915. Prosser resigned in 1886, moved to Australia and died in Sydney in 1896. The firm continued operating under the Kempthorne Prosser name, expanding its factories, offices and distribution network. During the 1970s, farmer dissatisfaction with the structure of the fertiliser industry encouraged the creation of a producer-controlled cooperative. Ravensdown Fertiliser Co-operative, supported by Brierley Investments and producer-board funds, acquired Kempthorne Prosser in 1978. The acquisition ended the company’s independent existence. Some of its former plants and buildings were demolished, repurposed or incorporated into later fertiliser operations, leaving an industrial and agricultural legacy rather than an active standalone brand.

1. 1978Acquisition by Ravensdown

   Ravensdown Fertiliser Co-operative acquired Kempthorne Prosser, ending its independent operation.

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2. 1926Wanganui Chemical Works opens

   The company opened a further plant at Aramoho in Wanganui.

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3. 1922Hornby Chemical Works opens

   A new chemical works was established at Hornby in Christchurch.

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4. 1887Westfield Chemical Works opens

   The company expanded its fertiliser manufacturing network to Westfield in Auckland.

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5. 1881Burnside Chemical Works opens

   The Dunedin works began producing superphosphate, helping launch New Zealand’s domestic chemical fertiliser industry.

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6. 1879The business becomes a limited-liability company

   Kempthorne Prosser & Co. adopted a limited-liability corporate structure and became associated with the New Zealand Drug Company.

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7. 1870Kempthorne and Prosser form a Dunedin chemist business

   Thomas Whitelock Kempthorne and Evan Prosser entered partnership in Dunedin, establishing the business that became Kempthorne Prosser.

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A vertically integrated New Zealand drug and chemical manufacturer whose business expanded into nationally important fertiliser production and agricultural supply.

• K.P. LifesaltConsumer health product1920

  A mineral-salt drink associated with Kempthorne Prosser’s consumer pharmaceutical range. It was marketed from the late 1920s and remained available into at least the 1940s, when it faced competition from Andrew’s Liver Salts.

• KP Rockland ManuresAgricultural fertiliser

  A branded fertiliser line produced through Kempthorne Prosser’s chemical-works network. It represented the company’s long-running role in supplying fertilisers to New Zealand farmers.

• Westfield ManuresAgricultural fertiliser

  Fertiliser products associated with the Westfield works in Auckland. The line formed part of Kempthorne Prosser’s agricultural portfolio during its period of national fertiliser-market influence.

• Flavouring essencesChemical and household product

  Kempthorne Prosser produced flavouring essences in several varieties as part of its wider drugstore and chemical range. Sources describe as many as eight flavours.

1. Kempthorne Prosser
2. From Eau de Cologne to Rat Poison: Kempthorne Prosser and Co.'s New Zealand Drug Co. Ltd., 1869–1918
3. Messrs Kempthorne, Prosser and Co.'s Premises
4. Kempthorne Prosser historical material