72 Scientific InteUigence. [July 



stretched over the extremity of a conical vessel, with a bit of wood 

 so adjusted, as to admit of being pressed at pleasure to the membrane. 

 Dr. Faraday concluded by stating, that the phenomena of electricity 

 are similar to vibration, and that they appear, (though he spoke 

 diffidently) to him to be closely analogous, and that the phenomena 

 of light are best explained on the same principles. Chemistry, he 

 observed, was nothing but electricity. Hence, all philosophers are 

 now looking out for a general principle, much higher than gravitation. 



22nc^ May. — Mr. Brockden gave an account of the devastation 

 occasioned by the great storm among the Alps, in August, 1834, 

 when property to the amount of many millions of florins was utterly 

 destroyed. The facts which he brought forward were derived from 

 travellers. 



'2Qth May. — Mr. Davidson on the ancient Egyptian City of 

 Thebes. 



Sth June. — Mr. Cooper on Engraving and Marble Sculpture. 



11.— Diseases of the larch. ^ 



According to Mr. Stephens of Edinburgh, who has addressed a 

 letter to De CandoUe upon the subject, the larch ( Lar'ix Europcea), 

 is subject in Great Britain to two diseases. The first disease consists 

 in the decay of the heart of the wood. It occurs not only in wet 

 situations, but also in dry places, as in Nottinghamshire, where 

 immense losses have been sustained. It has only manifested a slight 

 appearance at Dunkeld, and is most prevalent in England. The 

 larch has been found not to thrive, where Scotch fir {Pinus St/l- 

 vest7'is) has previously existed ; but this is not the cause of the dis- 

 ease. Another disease to which it is subject, is a blister, which 

 forms about 2 feet above the ground. These blisters are produced 

 on two sides of the tree alternately, until they reach the top, when 

 the tree dies from above downwards as it were. Sometimes the 

 blister surrounds a branch, which breaks off in the course of time. 

 This accident is frequently ascribed to the weight of snow. The 

 range of this disease is at present bounded by the county of Forfar, 

 and the south of the Grampians. It attacks entire plantations, but 

 rarely trees above 25 years of age, and is most destructive in poor 

 soils, or on hard formations, as clinkstone. 



None of the Dunkeld trees, at an elevation of 1000 feet have 

 been affected. 



De'Candolle states, that on the Alps, the larch is free from any 

 disease, save the occasional loss of its leaves by the attacks of a cater- 

 pillar, and a resinous blister or cancer, which however, produce no 

 injurious effect upon the tree. It grows extremely well at Moritz- 

 burg, near Dresden, in a moist sandy soil, 238 feet above the sea. 

 He proposes for this country the following recommendations : 



1. That the higher parts of the country are best suited for its 



* Bibliotheque Universelle, February, 1835. 



