Destitute as these broad stretches of barrenness are of springs, or running brooks, yet at times they are swept by terrific storms, when torrents dash down the mountain side, and plow deep furrows in the sandy waste. The dry beds which they leave behind are wadies. These wadies, depressed below the level of the surrounding plain, are the favorite places for pitching tents, as the banks on either side furnish a shelter from the winds that sweep over the desert. Several of these we crossed to-day, in which the half-dried mud showed that there had been recent rains. Wherever the moisture had touched, there were signs of vegetation. Dr. Post, who is always on the lookout for such treasures, found twenty new species of plants in one day, which he displayed with the delight of a discoverer, pointing out how nature had provided sustenance for them by furnishing them with thick leaves or long roots or little warts, which the microscope showed to be so many minute cells or sacs for water. Every traveller will have his attention called by his camel, if not by his guide, to a thorny bush of which the camel is very fond. Nor will the rider, if he be wise, urge on the poor beast which stops a moment to crop its leaves, for it is very aromatic, and sends up a fragrant smell into his face. Another bush which is common is the juniper — more properly the "broom" of the desert — under which we often found a shade for our midday meal.
Twice to-day were we reminded that we were on the track of the Israelites — once at Marah, the spring whose very name tells of its bitterness, and which, however sweetened by Moses, still disappoints the traveller, for indeed it is almost dried up. We found in it no flowing water at all; only digging in the sand, we discovered where a hidden spring was oozing away. A much larger spring, or group of springs, we found at Wady Ghurundel, the Elim of the
