54 SCIENTIFIC ILLUSTRATIONS [Com 



aromatic, has many extremely remarkable properties. Its milky 

 juice exhales, when burnt, an ammoniacal odour, and chemical 

 analysis has recognised therein the presence of fibrine. Mix 

 some of this juice in water, plunge into the mixture fresh hard 

 meat, and in a few minutes it will become exquisitely tender. 

 The very exhalations of the tree operate in the same manner, 

 and the inhabitants of the regions where it nourishes suspend 

 to its branches such meat and poultry as they wish to soften. 

 Wondrous combination of beauty and utility ! D. 



Combination is Strength. 



The house martin (Chelidon urbicd), our common summer 

 visitor to all parts of Europe, seems quite to understand that 

 combination is strength. These birds possess some sort of 

 intelligence with each other which enables them to combine 

 their efforts to effect some desired purpose. Dupont de 

 Nemours says "I once saw a martin which had unfor- 

 tunately, I know not how, caught its foot in the running knot 

 of a thread, the other end of which was attached to a gutter of 

 the College des Quatre Nations. Its strength being exhausted, 

 it hung and cried at the end of the thread, which it raised 

 sometimes by trying to fly away. All the martins of the great 

 basin between the bridge of the Tuileries and the Pont Neuf, 

 and perhaps from a still greater distance, collected to the 

 number of several thousands. They formed a cloud, all emitting 

 cries of alarm and pity. After much hesitation and a tumul- 

 tuous consultation, one of them invented a mode of delivering 

 their companion, made the others understand it, and commenced 

 its execution. All those that were within reach came in turn, 

 as if running at the ring, and gave a peck to the thread in 

 passing. These blows, all directed upon the same point, 

 succeeded each other every second, or even still more frequently. 

 Half an hour of this work was sufficient to cut through the 

 thread, and set the captive at liberty." No union of men for a 

 common purpose could more completely illustrate the truth that 

 combination is strength. MU. 



