146 



ttat on the first introduction of the tree into this country, the male tree 

 alone was propagated. The female, however, is coming more rapidly 

 into use, and may readily be known by the clusters of seeds it bears, 

 similar to those of some species of the ash family. 



There are lew trees more valuable for timber tliau the ailanthus. The 

 wood has much of the same properties as the chestnut, and is equally 

 durable, grows with as great rapidity, and in its native country obtains 

 a height of between two and three hundred feet. It is said to be well 

 adapted to growth on the western prairies, and will undoubtedly per- 

 form an important part in clothing them with forest vegetation. 



Purification of oil. — Of farious methods adopted for the purifica- 

 tion of burning-oils, that of Miehaud is recommended as the most satis- 

 factory. This consists in introducing sulphuric acid into the oil in nu- 

 merous thin streams, while air is forced in at the same time, so as to 

 throw the liquid into an active movement. The air bubbles which mix 

 with the oil give it a milky appearance, and carry the impurities with 

 them to the surface and form a copious scum, Mhich is removed from 

 time to time. After each skimming air is introduced anew until the 

 surface continues entirely clear. 



For the puri)0se of freeing the oil from sulphuric acid it is then to be 

 placed in a copper kettle, and steam introduced until it is heated to 

 212°. At this temperature it is kept for half or three-quarters of an 

 hour, during which it becomes sufficiently clear to be filtered. The oil 

 is then drawn off and allowed to cool down to half the temperature inen- 

 tioned, either by allowing it to stand for twenty-four hours, or taking- 

 it through a cooling tube and then filtering it. It is said that oil, treated 

 in this way, exceeds in illuminating power and transparency that pre- 

 pared by any other method, while the process is neither costlj^ nor pro- 

 tracted. 



Darlingtonia Californica. — Mr. Worthington G. Smith calls 

 attention in "Nature" to certain living plants of Darlingtonla Calif or- 

 nica, or the American pitcher plant, described many years ago in the 

 Smithsonian Contributions, hj Dr. Torrey, from specimens brought by 

 General Fremont from what is now Nevada. According to Mr. Smith, 

 the plant possesses an irresistible attraction to insects, the nature of 

 which is entirely unaccountable. When in bloom the flower is said to 

 resemble the upraised head and body of the cobra, with mouth ex- 

 panded, and prepared for a spring, the head being at right angles with 

 the hollow, vertical body, and api)arently presenting no opening by 

 which an insect can enter. Blue bottle or blow flies are said to make 

 their way immediately to this plant whenever they come into a room 

 where it is growing, and alighting on a portion of the flower, they fly 

 upward into the previously unseen entrance to the tube, and from this 

 they descend the hollow body, and apparently never return alive, keep- 

 ing up a buzzing noise for half an hour and then dying. This cavity of 

 the plant soon becomes entirely filled with dead flies, so that, as a con- 

 sequence, the walls decay and the insects drop out. 



Leached ashes as a manure. — An agricultural journal of Germany 

 calls renewed attention to the great value, as a manure, of soap-boilers' 

 leached ashes, which, as is well known, are prepared by mixing wood- 

 ashes with fresh burnt lime, and boiling or leaching the two together 

 for the pur])ose of obtaining a caustic lye. Although the soluble salts 

 are removed from these ashes, the insoluble parts remain, namely, the 

 carbonates, sulphates, and phosphates, principally lime salts, accom- 

 panied generally by a little causti{; lime. Experience has shown that 



