THE AMERICAN BOTANIST. 57 



of camphor is a government monopoh' and on account of 

 the w^ar in which the countrj^ is now engaged the supplies 

 of crude camphor have been held back. As a consequence, 

 the price of camphor has nearh' doubled. Camphor is ob- 

 tained by distillation from the wood of the tree which is 

 cut into small pieces for the purpose. It has also been 

 made synthetically in America. 



Durability of Catalpa and Locust. — The threat- 

 ened shortage in stock for railway ties has turned the at- 

 tention of railway companies to the question of where the 

 supplies of the future are to be obtained. The Illinois 

 Central and several others are attempting to solve the 

 problem by the extensive planting of timber along the 

 right of way. The Catalpa (C. speciosa) is the favorite 

 for such plantings since it grows rapidly and makes a 

 strong durable timber, but the locust {Robinia pseudacca- 

 cia) has even stronger claims to recognition for it grows 

 as rapidly and the wood is of even greater durability. The 

 editor has seen a locust fence-post that has done duty in 

 sun and storm for seventj^ years. 



Salt and the Thickness of Leaves.— M. A. Chrysler 

 has been measuring the thickness of the leaves of various 

 seaside plants and comparing these with the thickness of 

 leaves from similar plants growing on the shores of Lake 

 Michigan. In the June Botanical Gazette the statement 

 is made that in every case the maritime plants had thicker 

 leaves than similar plants inland. The cause for this 

 seems to be the salt in the sea-coast habitat. This is quite 

 in line with the practice of farmers who often salt the 

 earth about their cabbages for the beneficial effect it has 

 upon the plants, perhaps without knowing why cabbages 

 like salt when other vegetables do not. The cabbage once 

 grew wild along the sea-coast and so, of course, salt is a 

 famihar element to it. 



