The company hospital of the Deli tobacco Company at Toentoengan estate was established in 1885. It was a general hospital  situated high in the mountains. The Tropen Museum disposes of a picture dated 1885-1888 with legend “Ziekenhuis voor contractarbeiders bij de tabaksplantage Toentoengan. (TM 60001489). M.Watson calls the Toentoengan Estate a typical hill land estate, free from malaria. It is the highest estate of the Deli Company, situated between 200 and 300 feet above sea-level. “From the road the path runs for about half a mile on the level, but surrounded on all sides by the curious bank-like hills seen in Sumatra. On the left was was jungle, the boundary of the estate. In the flat portion of the estate was a small stream and a number of drains; in the stream no larvae were found, nor was my search in the drains more fruitful until I reached their upper ends. Here, especially in one drain, where there was grass, I took many Culex larvae, but no Anopheles……………………” Further: “The labour force  consisted last year of 1200 coolies,of whom 1,000 were indentured. Of this force nine died in hospital and one on the estate, which gives a death rate of 8.3 ‰. From a consideration of of these figures, from my failure to obtain larvae in the streams and the adult insects in the lines, it is apparent the health of this labour force is infinitely better than it would be on a corresponding hilly estate in the Federal Malay States, and the conclusion is suggested that this is due to the absence of malaria.” (Malcolm Watson, Rural situation in the Tropics, being notes and observations in the Malay Archipelago, Panama and other lands, London 1915), 59-89 (Ch. VI, Notes on Sumatra).