CHAPTER VI.

SUBURBS OF CAIRO-HELOUAN-LES-BAINS—

PYRAMIDS-MATARIYEH.

HELOUAN is an artificial oasis in the desert, three miles from the right bank of the Nile, and fifteen miles south of Cairo. The railway connecting it with the capital has in 1889 been brought into the centre of the town, and various other improvements have been made by the company to whom the railway now belongs. The trains run to and fro in forty minutes, and six times a day. The village consists of a palace built by the present Khedive, two hotels, about a hundred and fifty detached private houses, and two engines for pumping up Nile water. It is about 112 feet above the Nile level, on a firm plateau of sand, and is famous for a remarkably pure, dry, and dustless atmosphere. It is surrounded on all sides by the desert, and on the east by the continuation of the Mokattam range of hills. But the property which makes the

table-land of Helouan remarkable is that it is in some places saturated with water like a sponge. Water is found at a depth varying from ten inches to ten feet, and, when coming out of the springs, has a temperature of 77° or 85° Fahr., and the yield from these springs is considerable. The water of the sulphur springs is quite clear and colourless, but, on being exposed for a short time to the air, the surface becomes covered with a slight film of sulphur and lime-salts. The water smells a little of sulphuretted hydrogen, and is slightly saltish without being unpleasant to drink. Up to the present twelve springs have been discovered, and may be divided into three classes-Sulphur, Iron, and Saline.

1. Two of the Sulphur springs supply the Baths which are attached to the chief hotel, and a third has been led into a fountain, where the poor of the neighbourhood come to drink gratis. Temperature, 86° Fahr.; specific gravity, 1.0025.

GASTINEL BEY'S ANALYSIS OF ONE LITRE (35 FLUID OZ.).

There are two other sulphur springs, less warm and containing much more salt, but they are not being used at present. The sulphur waters resemble those of Aix-les-Bains and Enghien (Paris).

2. There are two Iron springs, the water of which is pleasant to drink and is taken gratis by large numbers of people. The bicarbonate of iron in the water comes from the protoxide of iron in the sand. The sand, which in the spring is black, takes a yellowish-grey colour when dried in the air, the protoxide being turned into sesquioxide of iron. The water is clear, colourless, odourless, and tastes a little salt and bitter. Temperature, 77° Fahr.; specific gravity, 1.0445. It does not leave a deposit of carbonate of iron when exposed to the air.

Lovers of this water take it for its aperient rather than its ferruginous effect.

3. There is only one Saline spring; the water acts as a purgative, and is bottled to be drunk at leisure by its devotees. The water, like the others, is clear, colourless, and without odour, and has a slight salt, bitter taste. Temperature, 77° Fahr.; specific gravity, 1.0152.

But, though I give an analysis of all three kinds of waters, the only important one at present is the sulphur variety. It owes its sulphur properties to the chemical processes which sulphate of lime, meeting with nitrogenous matter and becoming sulphate of calcium, produces by setting free carbonic acid and nitrogen from the decomposition of the nitrogenous matter. Then the carbonic acid decomposes the sulphate of calcium and forms carbonate of lime, which, in presence of an excess of carbonic acid and under great pressure, is converted into a very soluble bicarbonate of lime, which at last sets free sulphuretted hydrogen gas. The nitrogenous organic matter which is found in all the Helouan waters has been named Barégine, because it was first discovered in the Baréges waters of the Pyrenees. It is found in all sulphur waters when exposed to light and air, and is the cause of the greenish vegetation which collects round the edges of stagnant sulphur water. The sulphur is sufficiently strong in the air to turn silver ornaments black, but after the first day one ceases to notice the odour.

History. The village is said to take its name from the great grandson of a certain untraceable king of Egypt. It is known to have been frequented in A.D. 690, and at other times by notables who were driven out of Old Cairo by the plague,