MISCELLANEOUS. 26i 



meaning of a few words I heard with profit many years 

 ago in a Protestant church in the charming Swiss 

 valley of Lucerne. The preacher was enlarging upon 

 the Christian's hold of the Saviour, and he besought 

 his hearers to " cling to Him as the limpet does to the 

 rock." I remember with thankfulness the words, and 

 they were those. The newspaper correspondent tells us 

 how the limpet does cling to the rock. He speaks 

 first of its amazing power of doing so. "An ordinary 

 limpet, the common species of our coast, weighs, when 

 deprived of its shell, within a fraction of half an ounce. 

 Yet, when pulled in the line of its plane of adhesion, 

 a force exceeding sixty-two pounds is required to loosen 

 its powerful grip upon the rock, or, in other words, 

 upwards of 1984 times the mollusc's own weight. An 

 ingenious calculation has also been made as to the in- 

 fluence of atmospheric pressure in the operation. Thus, 

 the superficial base of the individual limpet is about 2-4 

 square inches, which, taking the pressure of the air at 

 li'7 pounds on the square inch, would only account for 

 something over thirty-five pounds and a quarter or 

 little more than half the power exercised in the air by 

 the shell-fish. In the water its tenacity is even greater, 

 so that merely meteorological dynamics fail to explain the 

 tenacity of the little beast. Nor will muscular strength 

 account for it. Many molluscs are, as we know, very 

 powerful. Before an oyster can be opened, a force 1319J 

 times its weight must be exerted. If the limpet be 

 divided vertically from top to bottom as it stands on the 

 rock, and two other deep incisions be made in a horizontal 

 direction, thus destroying all the muscular power of the 

 base, and any possible vacuum between it and the rock, 

 the adhesion, nevertheless, continues as firm as before. 

 Even the death of the animal u does not destroy its 



