630 



THE POPULAR SCIENCE MONTHLY. 



points far distant and belonging to another 

 zone. Tiiis appears most distinctly in the 

 storms which accompany electrical displays. 

 The peculiar intermediate position which 

 the weather curve takes between the curves 

 of sun-spots and temperature may possibly 

 find its explanation in this fact. Observa- 

 tions recently published in Saxony confirm 

 these conclusions in a striking manner. 



Volcanle Outbreaks in Iceland. Since 

 the beginning of the present year volcanic 

 action has been almost incessant in Iceland. 

 The following particulars of the outbreaks 

 we find in Nature : In March the Dyngjuf- 

 joll was incessantly vomiting fire, and the 

 eruption was steadily spreading over the 

 wilderness. The farmers in the region 

 around the My-vatn Mountains were obliged 

 to remove in order to find pasture for their 

 stock, the country being covered with ashes. 

 Early in April a new eruption had broken 

 out in a southeasterly direction from Bar- 

 fell. A party went out from Laxardal to 

 explore, and on approaching the place of 

 eruption they found the fire rising up from 

 three lava-craters. At a distance of 100 

 to 150 yards to the west from the cra- 

 ters a large fissure had formed itself as the 

 fire broke out, and the land had sunk in to 

 the depth of about 18 feet. Into the hol- 

 low thus formed the lava had poured at 

 first, but now it flowed in a southwest direc- 

 tion from the two southern craters. The 

 northernmost crater had the appearance of 

 being oblong, about 600 yards in length, 

 and from this crater the molten red-hot lava 

 was thrown about 200 or 300 feet into the 

 air in one compact column. The top of 

 this column then assumed a palmated ap- 

 pearance, and the lava fell down in small 

 particles, hke drops from a jet of water, 

 which, as they became separated from the 

 column, grew gradually darker, and split 

 into many pieces, bursting into lesser and 

 lesser fragments as they cooled. No flames 

 were observed, but the glare proceeded from 

 these columns and the seething lava in the 

 craters. At times the explorers could count 

 twenty to thirty of these columns. No real 

 smoke accompanied the eruption, but a blu- 

 ish stream, which expanded and whitened 

 in color as it rose to a greater distance from 

 the crater ; and such seemed to be the pow- 



er of this blue jet of steam that it rose 

 straight into the air for many thousand 

 feet, despite a heavy wind blowing. 



How we keep our Mouths shut. Bon- 

 ders asserts that the mouth is kepi closed, 

 not by the action of the muscles connected 

 with the lower jaw, but by atmospheric 

 pressure. He has investigated this phe- 

 nomenon experimentally. By employing a 

 manometer, communicating with the space 

 between the tongue and the hard palate, he 

 finds, when the mouth is kept shut, a nega- 

 tive pressure corresponding to from two to 

 four millimetres of the mercurial column. 

 There are two suctorial spaces in the mouth : 

 the principal one is bounded by the tongue 

 below, the hard palate above, and the soft 

 palate behind ; the other is situated be- 

 tween the tongue and the floor of the 

 mouth. The former is used in sucking 

 hquid through a straw ; the latter (some- 

 times) in smoking. Both are employed 

 when we endeavor, with the mouth closed, 

 to extract a foreign body from between the 

 teeth. The mouth may be shut during 

 sleep, when the muscles of mastication are 

 relaxed. If a man fall asleep in the sitting 

 posture with his mouth open, his jaw drops ; 

 the tongue not bemg in contact with the 

 hard palate, the suctorial space is oblit- 

 erated; the soft palate no longer adheres 

 to the root of the tongue ; and, if respira- 

 tion be carried on through the mouth, the 

 muscular curtain begins to vibrate, and 

 snoring is the result. 



Aliaskan and ilentian Maniinies. The 



custom of preserving or mummifying the 

 bodies of the dead, as formerly practised 

 by the natives of the islands in Behring 

 Sea, is accounted for very ingeniously by 

 Mr. William H. Ball, in the American Natu- 

 ralist. On the main-land, either on the Asi- 

 atic or the American side, the custom does 

 not appear ever to have existed. In the 

 Chukchee Peninsula, on the Asiatic side, 

 there is no soil in which to bury the dead, 

 and cremation is impossible from the want 

 of wood ; hence the natives expose their 

 dead to the tender mercies of bears, dogs, 

 and foxes. In the Yukon Valley, Alaska, 

 the soil is frozen hard, and excavation is 

 extremely difificult ; but timber abounds, 



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