764. 



THE POPULAR SCIENCE MONTHLY. 



found in clay-beds ; only their leaves fill 

 them just as the radicles of water-plants fill 

 the clay of the Tertiary lignite. It is, how- 

 ever, a fact that some of the lignite clay- 

 beds, and those of the coal-measures, too, 

 are clean or without admixture of vegetable 

 remains, even of rootlets. But when the 

 peat is beginning its growth at the surface 

 of a somewhat deep basin of water, whose 

 bottom has been rendered impermeable by 

 the deposit of clay (which always precedes 

 the deposit of woody materials), this sur- 

 face-peat is often thick and compact before 

 it is forced down and comes in contact with 

 the clay ; and, in that case, therefore, the 

 clay is pure, or is not penetrated by roots or 

 rootlets. There are, of course, some beds 

 of impure lignite, whose origin is due to 

 drifted wood, especially along large rivers. 

 One is known at the mouth of the Rhone, 

 in France. I have seen some deposits of 

 the kind in Southeastern Arkansas, near 

 the "Wachita River. The great Red-River 

 obstructions may become in time lignite- 

 deposits. But all formations of this kind 

 show their origin by their composition, viz., 

 sand mixed with carbonized matter, sandy 

 bottom, perforated, too, in various direc- 

 tions by drifted stems, etc. Nothing of this 

 kind has been observed in the beds of lig- 

 nite of the West, at least not in those which 

 have come under my examination." 



Geology of the Land of Moab. — Late 

 explorations in the land of Moab by Dr. 

 Tristam have disclosed some interesting 

 geological features in that region. The 

 doctor's observations were mainly confined 

 to the highlands, which are in reality a 

 set of terraces, or table-lands, rising to 

 the eastward from the shores of the Dead 

 Sea — attaining, in a distance of 35 miles, 

 a height of between 4,000 and 5,000 feet. 

 These table-lands are cut at right angles 

 into deep gorges or ravines, by streams 

 which now flow, or at some former 

 time have flowed, westward into the Dead 

 Sea. Some of the gorges are 1,800 feet 

 deep, with perpendicular walls, from which 

 a good idea of the geological structure of 

 the region may be obtained. The surface 

 of these highlands is composed of chalk, 

 which rests upon a limestone formation, re- 

 garded by some as nummulitic and by 



others as Jurassic. The chalk and lime- 

 stone together are from 1,200 to 1,500 feet 

 thick. The limestone is supported by new 

 red sandstone, the line where they join being 

 well defined. It is from this line of junc- 

 tion that the hot springs, so celebrated in 

 Roman times, gush forth. The water of 

 these springs has a temperature varying 

 from 100° to 143° Fahr. The salt-hills at 

 the south of the Dead Sea, like the table- 

 lands just spoken of, have been gouged out 

 by the action of water, and present along 

 their face numerous columns and pinnacles 

 of salt, that are being rapidly worn down 

 by the action of the weather. 



Etiology of Typhoid Fever. — Prof. I. 

 Buckman writes to the Gardener's Chronicle 

 concerning the discovery of a microscopic 

 fungus in water, the drinking of which was 

 suspected of developing cases of typhoid fe- 

 ver. "We give the main points of this com- 

 munication. Some years ago Prof. Buck- 

 man examined the spout of a pump which 

 had supplied water to a family attacked by 

 typhoid. It was found to be lined with ge- 

 latinous matter. Under the microscope this 

 substance was seen to contain some elegant 

 branched confervoid or fungoid growths, in- 

 termixed with which were minute ovoid cells. 

 As these fungoids require nitrogen for their 

 nourishment, the author inferred that the 

 supply came from some neighboring cess- 

 pool He next went to the exit-drain of the 

 town sewerage, and there found bits of 

 sticks, leaves of water-plants, and the like, 

 more or less covered with this same gelati- 

 nous matter. 



The author next detected this fungus in 

 water used by his own family, some of 

 whose members were severely attacked with 

 typhoid fever. A defective drain in the 

 neighborhood of the dwelling having been 

 set to rights, and the whole of the water 

 pumped out, the water has since been of 

 excellent purity. Having cited two other 

 analogous cases, Prof. Buckman speculates 

 as follows on the mode in which this fungus 

 acts after having been admitted into the 

 animal economy : " How it acts it would be 

 difficult to determine, but it is at least con- 

 ceivable that the spores of the fungus may 

 get into the circulation, and bring about 

 changes in the fluids, after the manner of 



