Sulphurous fumes which were combustible were belched out of the earth at the time of the Jamaica earthquake in 1692. The smell which accompanied this was so powerful that it caused a general sickness which swept away about 3,000 persons.[43] From the fissures formed at Concepcion in 1835, water, which was black and fœtid, issued.[44] The earthquakes of New England in 1727 were accompanied by the formation of fissures, from which sand and water boiled out in sufficient quantity to form a quagmire. In some places ash and sulphur are said to have been ejected. At one house the stink of sulphur accompanying the earthquake was so great that the family could not bear to remain in doors.[45] Emanations of gas sometimes appear to have burst out from submarine sources. Thus the earthquake at Lima, in March, 1865, was accompanied with great agitation of the water and an odour of sulphuretted and carburetted hydrogen. This former gas was developed to such an extent that the white paint of the U.S. ship ‘Lancaster’ was blackened.[46] With the smell, flames have sometimes been observed, as, for instance, at the time of the Lisbon earthquake. At the time of the earthquakes of 1811 and 1813, in the Mississippi valley, steam and smoke issued from some of the fissures which were formed. Instances are recorded where stones have been shot up from fissures unaccompanied by water, as, for instance, at the earthquake of Pasto (January, 1834). It is imagined that the propelling power must have been the sudden expansion of escaping gases. It has been suggested that flames seen above fissures might perhaps be due to the burning of materials like sulphur. Mr. D. Forbes, who examined the effects of the earthquakes of Mendoza, which were felt for a distance of 1,200 miles, says that where the hard rock came to the surface there were no traces of fissures, these being entirely confined to the alluvium. The rumours of fire and smoke having appeared at some of the fissures were without foundation, the presumed smoke being nothing but dust.[47] In addition to flames lights appear often to have been observed, the origin of which cannot be easily explained. The earthquake of November 22, 1751, at Genoa is said to have been accompanied by a light like that of a prodigious fire which seemed to arise out of the ground.[48] _Explanation of fissure phenomena._—The manner in which fissures are formed has already been explained when referring to the want of support in the face of hills (page 136).