140 



THE POPULAR SCIENCE MONTHLY. 



the earlier years of this century, and whose 

 surface was estimated at five hundred and 

 thirty square miles, only three small ponds 

 have remained. Even twcntj'-five years 

 ago there were several lakes, ten and eight 

 miles long and wide, where there are now 

 but little ponds. The fate of Lake Abysh- 

 kan is substantially repeated in Lake Che- 

 bakly, which was represented in 1784 as 

 an oval body forty miles long and three 

 miles wide. Kow, the largest of the three 

 ponds which occupy its site is less than two 

 miles wide. The same process is going on 

 throughout the lakes of West Siberia and 

 throughout the Aral-Caspian depression. 



Electric Deposition of Dust. — Professor 

 T}iidall observed, in 1870, that when a hot 

 body was held in strongly-illuminated, dusty 

 air, a dust-free space was formed above it, 

 and this may take place even • when the 

 body is only slightly warmer than the air. 

 Several hypothetical explanations of the 

 phenomenon have been offered by Dr. Tyn- 

 dall, Dr. Frankland, and Lord Rayleigh, but 

 they have been inadequate to meet the re- 

 quirements of the case. Professor Oliver 

 Lodge has sought an explanation by the 

 application of the kinetic theory of gases, 

 and supposes that the dust-particles are 

 kept out of contact with the warm body by 

 means of a differential molecular bombard- 

 ment of their surfaces. On the other hand, 

 with the singular and not explained excep- 

 tion, that a similar dark plane, but descend- 

 ing, is formed below a moderately cool 

 body, the dust-particles are driven toward, 

 instead of away from, a cold body. This 

 fact has been observed by Mr. Aitken, and 

 applied by himself to the explanation of 

 the deposition of soot in chimneys, and of 

 lamp-black on cold glass. The result of 

 the dust-bombardment of cold bodies may 

 also be seen in the blackening of a wall 

 over hot-water pipes, or of a ceiling over a 

 gas-jet. Smoking of the gas-jet will, of 

 course, provide more material to be depos- 

 ited, but the dust and smoke in the air are 

 usually ample to effect a sufficient blacken- 

 ing over even a perfectly clear flame. An 

 incandescent electric lamp, hung a foot or 

 so under a white ceiling, will similarly cause 

 a small, black patch. In rooms warmed by 

 radiation, objects are warmer than the air 



and keep much dust off themselves. In 

 stove-heated rooms, things are liable to be 

 colder than the air, and thus get exceed- 

 ingly dusty. Professor Lodge supposes, 

 also, that electrical conditions may have 

 much to do with the matter, and relates sev- 

 eral experiments which he has made that 

 go to confirm this view. One of them is 

 made with a minute, vertical water-jet 

 which usually scatters into drops and falls 

 in a shower-like rain ; but hold a piece of 

 rubbed sealing-wax a yard or so distant 

 from the place where the jet breaks, and 

 the drops at once cease to scatter, but fall 

 in large blobs, as in a thunder-shower. 

 These principles are susceptible of applica- 

 tion in many processes where dust is gen- 

 erated in quantities that make it a nui- 

 sance for laying it. Thus, chimney-flues 

 may be fitted with spikes or wire nettings, 

 which will cause the smoke to be con- 

 densed, and the dust to be deposited. So,, 

 on a larger scale, the introduction of elec- 

 trical action into a cloud is supposed to 

 give rise to rain. 



Origin of Strong Liqnors. — Strong liq- 

 uors are a modern invention. The an- 

 cients knew of nothing more powerful than 

 lightly fermented wines, and have left 

 warnings enough of the abuse of them. Al- 

 cohol was not discovered till the seventh 

 century, although an older story exists of 

 a monk, Marcus, who collected and con- 

 densed in wool the steam of heated white- 

 wine, and then pressed out from the wool 

 a balsam which he applied to the wounds of 

 those who fell at the siege of Rheims, in 

 the reign of Clovis I. lie also mixed this 

 balsam with honey, and produced a cordial 

 which brought the moribund back to life. 

 Clovis, however, did not wait for the ap- 

 proach of death, before claiming his share 

 of the cordial. According to Dr. Stanford 

 Chaille, the distillation of spirits from wine 

 was not discovered till the twelfth century, 

 and spirits did not come into common use 

 as drinks until the fifteenth, sixteenth, and 

 seventeenth centuries. Professor Arnoldus 

 de Villanova, in the fourteenth century, 

 made a panacea of the water-of-life, which 

 gave sweet breath, and fortified the mem- 

 ory, besides being good for sore eyes, the 

 toothache, and the gout, and having other 



