[FOR THE USE OF MEMBERS. | 
Royal Fustitution of Great Writatn. 
1851. 
WEEKLY EVENING MEETING, 
Friday, May 16. 
Tue Lorp OversTone, Vice President, in the Chair. 
Captain W. H. Suipparp, 
On Central America and the Ship-Canal. 
Captain Shippard commenced by alluding to the very great impor- 
tance of communications, whether by canal or railway, through the 
Isthmuses of Suez and Darien. He then referred to the various 
modes proposed for traversing the latter, and stated what he 
conceived to be the advantages that would result from a ship- 
canal through Nicaragua, referring throughout his discourse to a 
Relief Model before him, furnishmg the complete physical features of 
the country from the Port of Realejo on the Pacific, including 
the Lakes Leon and Nicaragua, down to the south of the Rio 
San Juan on the Atlantic, based upon the English, French, and 
Spanish Admiralty surveys, and upon French, Spanish, German, 
Dutch, and American authorities. 
He then read a series of notes respecting the political cha- 
racter, geographical features, and natural history of Central Ame- 
rica; and concluded by giving a historical sketch of the con- 
nexion between that country and the British Government, since 
the early part of the 17th century, by means of the Mosquito 
nation, the Governors of Jamaica, &c. 
Electric Currents in Plants. 
Mr. Farapay communicated a brief verbal notice of the results 
obtained by M. Becquerel in his recent researches into the nature 
and directions of the Electric currents which may, or do exist in 
the different parts of a tree or other plant; and also of those 
which exist im relation to the tree and the surrounding earth. By 
the insertion of terminals attached to the galvanometer into 
various parts of the tree, effects were obtained which indicated 
that the current is from both the bark and the heart-wood 
through the instrument to the cambium or parts between the bark 
and the wood. As regards the relation of the vegetative process 
to the atmosphere, the earth was found positive to the paren- 
No. 6. 
