MISCELLANY. 



125 



in such rocks, and then has the following as 

 to how they came there : " There is every 

 probability that originally the enveloping 

 matrix must have reached the fossils in the 

 shape of volcanic ash, or, more likely still, in 

 the shape of a thick fluid sediment envelop- 

 ing the trunks of the trees as they stood 

 erect, with their broken branches, leaves, and 

 fruit scattered around them. We have nu- 

 merous instances of ash-beds overlying lime- 

 stone-beds containing corals, and I suspect 

 Mr. Honeyman's ' trap rock in a fiuid state ' 

 would resolve itself into a rock of the na- 

 ture above indicated ; at all events, it would 

 be very interesting to geologists on this side 

 to receive specimens for closer examination. 

 With regard to the possibility of fossils 

 being inclosed and preserved in fluid lava, I 

 may mention that when at Catania, in 186Y, 

 I was informed by Prof Sylvestri that oak- 

 trees on Mount Etna, when overtaken by 

 lava-streams, are not actually annihilated, 

 but the lava forms a sort of hollow cylin- 

 der around the trees, in which they are car- 

 bonized, and the silex contained in the wood 

 collects in a fused mass at the bottom of 

 the trunk. Such fused masses I met with 

 at the foot of some of the stems of trees 

 excavated by me at Arran, and numerous 

 pebbles, evidently derived from the same 

 source, are to be picked up on the shore 

 between the Fallen Rocks and the Scriden 

 at the north end of Arran." 



Carioas Method of captaring Mnsk-rats. 



The American Sportsman describes the 

 ingenious method followed by trappers in 

 catching musk-rats : These animals often 

 travel great distances under ice. In their 

 winter excursions to their feeding-grounds 

 they take in breath at starting, and remain 

 under water as long as they can. They then 

 rise to the ice and exhale the air in their 

 lungs ; this remains in bubbles against the 

 under surface of the ice. They wait till 

 this air recovers oxygen from the water and 

 ice, and then, reinhaling it, go on till the 

 operation has to be repeated. In this way 

 they can travel almost any distance, and live 

 any length of time, under the ice. The trap- 

 per takes advantage of this habit. When 

 the marshes and ponds where musk-rats 

 abound are frozen over, and the ice is com- 

 paratively thin and clear, they can be seen 



swimming about beneath. Following one 

 for some distance, the trapper sees it come 

 up to renew its breath in the manner de- 

 scribed. After the animal has exhaled, and 

 before it has time to take in the reoxygen- 

 ized air in the bubbles again, he strikes 

 with his hatchet directly over it, scattering 

 the bubbles, and driving the musk-rat away. 

 In this case the rat drowns in swimming a 

 few rods, and the trapper, cutting a hole in 

 the ice, takes it out. Mink, otter, and bea- 

 ver, travel under the ice in the same way, 

 and hunters, it is, stated, frequently take 

 otters in the same manner. 



Edacation of Telegraph-Operators. In 



Holland the applicant for apprenticeship in 

 a telegraph-office is required to present a 

 thesis in Dutch; to be acquainted with 

 French, English, and German; to know the 

 first principles of arithmetic, common and 

 decimal fractions, and the metrical system 

 of weights and measures ; to have mastered 

 the rudiments of algebra and geometry, and 

 in geography to be familiar with the situa- 

 tion of the various countries and principal 

 towns. When an apprentice applies for the 

 position of a telegraphist of the third class, 

 he is required to pass an examination in mag- 

 netism, electro-magnetism, etc. in short, 

 to prove his familiarity with every detail of 

 telegraph administration. Remarking on 

 this, the Journal of the Telegraph says that 

 in this country the person who enters the 

 telegraphic service "must certainly know 

 his telegraphic letters and make them cor- 

 rectly ; must write a clear hand ; must have 

 a knowledge of circuits and office connec- 

 tions ; and must be informed respecting the 

 company's rules. Yet these simple require- 

 ments are objected to. 'I fear,' says the 

 manager of a large ofl5ce, ' if this were re- 

 quired here, I should be left almost alone.' 

 We ask, ' Can this ignorance of the com- 

 monest knowledge of a great business be 

 true ? ' We fear it is." 



How Water is injnred by Organic Mat- 

 ter. In a recent work entitled " Scientific 

 Conversations," by M. Porville, of Paris, 

 the reason why organic matter becomes a 

 dangerous constituent of water is thus set 

 forth : " How does organic matter become 

 dangerous? We must not beheve that it 



