546 FOURTH BULLETIN OT [1846. 



of three inches. This stately species appears different in habit from the small 

 species growing in the United States, where they only rt;aeh the height of a foot. 



Tliere is also a large tree found in the swamps, belonging to the order Anacar- 

 diaceae, and bears a large fruit, similar to the mango, but not edible. 



The province of Sambas is said to be very salubrious, not only with regard tothe 

 natives, but also Europeans. This would not be the conclusion arrived at from an 

 inspection of the country, which consists of extensive marshes principally, and a 

 lew rounded hills, whicii occur irregularly unconnected with a mountain chain. 



In the small Malayan village before mentioned the soil was a black marl, and 

 apparently overflowed at times, and when stirred up to the depth of a foot, emitted 

 ru almost insupportable stench, probably of sulphuretted hydrogen gas. This 

 condition appears irreconcilable with its salubrity. Dr. Ferguson has written a 

 treatise on the history and nature of marsh poison, (much referred to,) the result 

 of his investigations in Holland, Spain, Portugal, and the West Indites. He tries to 

 prove tht fact that the driest situations are very frequently, contrary to expecta- 

 tion, the most unhealthy. 



In his remarks he says, "one only condition seems indispensable to the produc- 

 tion of marsh poison on all surfaces capable of absorption, and that is the paucity 

 of water, where it has recently abounded. To this there is no exception in cli- 

 mates of high temperature, and from which we may justly infer that the poison is 

 produced at a highly advanced stage of the drying process." 



In another place Dr. Ferguson says, "it is from these, (the dried and half 

 dried margins of lakes and marshes,) that the poison uniformly emanates, and never 

 from the body of the lake or pond ; and I think it may be fairly presumed, that 

 water as long as it can preserve its particles above the surface is innoxious, and 

 that it must first be absorbed into the soil, and disappear before the eye, before it 

 can produce any mischievous effects. Whoever in malarious countries waits for 

 the evidence of putrefaction, will, in all the most dangerous places, wait too long ; 

 as every one can testify, who has seen pestilence teem forth to the paralyzation of 

 armies, from the bare barren sands of the Alentogo in Portugal, the arid burnt 

 plains of the Estremadurain Spain, and the recently flooded table lands of Barba- 

 does." 



Baron Humboldt, speaking of the intermittents which are so common near the 

 great cataracts of the river Orinoko, says, "the causes are violent heats, joined 

 with the excessive humidity of the air, bad nutriment, and, if we may believe the 

 natives, (as well as the missionaries, ) the pestilent exhalations that ari-e from the 

 bare rocks of the cataracts." Many persons arc spoken of, who, having passed the 

 night on the black and naked rock, have awakened in the morning with a strong 

 paroxysm of fever. Humboldt thinks that this is caused by the high temperj- 

 ture of the rocks, in consequence of their being coated over with a layer of the 

 oxide of manganese and iron. The higher temperature of these rocks is a very 

 doubtful cause ; but there is a relation between this fact and those mentioned by 

 Dr. Ferguson, of which the desiccation of nearly bare rocks in Spain, and of a 

 very thin bed of earth overlaying coral rocks in the West-Indios, has given rise to 

 the most pestiferous exhalation . 



I may also mention a fact corroborating Baron Humboldt's observations at the 

 cataracts. Singapore is celebrated for its salubrity, although having several marshes 

 extending into the town and the immediate neighborhood ;and I was informed by Dr. 

 Oxly, surgeon of the honorable East India Company, that but one case of malig- 

 nant fever had occurred to his knowledge since the place has been in the pusses- 

 sion of the English, since 1819. 



But an island in tho harbor, called " Blattcn Matte," about two and a half miles 

 distant from the town of Singapore, is notorious for being unhealthy. This island 

 I took occasion to visit in a Malay boat, and when passing one end whore the 

 rocks were exposed, I requested one to step out and break mo off a portion ; but 

 they all declined, saying that the people always took sick who went upon those 

 rocks, but were willing to pull a quarter of a mile farther, where they said they 

 could obtain some on the island. These rocks are composed of a coarse sandstone, 

 containing much oxide of iron, and coaled with blick oxide of manganese. I am 

 induced to believe tho opinions of these ignorant |)ooplo correct, for they have no 

 doubt been obtained from experience, for they are much accustomed to fishing 

 abgut these islands, and visiting thorn for tho purpose of obtaining pino-applcs. 



