25 April 1843: did Wesleyan missionary David Cargill, die in Tonga, of a self-administered overdose of opium?

at http://19thcenturyartofmourning.com/19th_century_laudanum_bottle.htm
Two versions exist of the death of David Cargill; in one, he dies of smallpox, and , the other, an over dose of laudanum (liquid opium). Cargill’s diaries – and other reports of him – show he wore a high sense of self-importance. He was perhaps, at first, tempered by the mild manner and community-popularity of his first wife, Margaret. David Cargill married again; but remained obsessed with his first wife; a woman who appeared to require, and retain, a saintly patience. The possibility of suicide appears implied in reportage.
The smallpox death-theory: ‘Cargill set foot once again in Vavou on 21st February 1843. On 29th March he preached twice in Tonguese and once in English. Within a month he was dead, succumbing to smallpox on 25th April’. wrote J. Malcolm Bulloch, in June, 1921.

The Dengue fever theory : http://www.mundus.ac.uk reported  ‘Cargill took over the superintendancy of the Vava’u Wesleyan mission from Peter Turner, and spent the next three months preaching at various mission stations, but was struck by dengue fever, leading to severe exhaustion. This illness, combined with continuing grief for the loss of his first wife, deepened the depression to which he was prone; he died of an overdose of laudanum on 25 April 1843’.
http://www.mundus.ac.uk/cgi-bin/search?coll_id=1038&inst_id=52&keyword=Tonga
“Laudanum”: The common name for Tincture of Opium, and the form in which that drug is most frequently administered. . . It is narcotic, sedative, and being made with spirit, is also, to a certain extent, stimulant and anti-spasmodic. For relieving pain, wherever situated, to diminish irritation, and to procure sleep, it is the best of the medicines we possess.” (From: The Family Doctor, a Dictionary of Domestic Medicine and Surgery, by a Dispensary Surgeon. London, c.1860) More, Small pox reference: (J. Malcolm Bulloch, June, 1921.)An Aberdeen graduate as pioneer in Fiji by J Malcolm Bulloch from the Aberdeen University Review, June 1921 http://myweb.tiscali.co.uk/wordscape/Cargill/Aberdeen.html