FRAGMENTS OF SCIENCE. 



427 



deciduous. It is probably the Fraxinus chi- 

 nensis, a species of ash. The tree is known 

 to the Chinese as pai la shu (white- wax tree). 

 On the arrival of the scales from the Chien- 

 ch'ang Valley, they are made up into small 

 packets of from twenty to thirty scales, 

 each inclosed in a leaf of the wood-oil tree. 

 The edges of the leaf are tied together with 

 rice straw, by which also the packet is sus- 

 pended close under the branches of the wax 

 tree. A few holes are made in the leaf, so 

 that the insects may find their way through 

 them to the branches. On emerging from the 

 scales the insects creep along the branches 

 to the leaves, where they stay for a period of 

 thirteen days. They then descend to the 

 branches and twigs, the females probably to 

 provide for a continuation of the race by 

 developing scales in which to deposit their 

 eggs, and the males to excrete the substance 

 known as white wax. Whether or not this 

 wax is normally intended as a protection for 

 the scales is uncertain. The wax first ap- 

 pears as a white coating on the under sides 

 of the boughs and twigs, and looks very much 

 like sulphate of quinine. It gradually spreads 

 over the whole branch, and attains after three 

 months a thickness of about a quarter of an 

 inch. The branches are then lopped off and 

 as much of the wax as possible removed by 

 hand. This is placed in a pot of boiling wa- 

 ter. The wax, melting, rises to the surface, 

 is skimmed off, and placed in a round mold, 

 whence it emerges as the white wax of com- 

 merce. An inferior darker quality is made 

 by boiling twigs and all together. When the 

 branches are lopped off a wax tree, a period 

 of three years is allowed to elapse before 

 the tree is again used. Since the introduc- 

 tion of kerosene oil into China the use and 

 hence production of this wax have much de- 

 creased, it having been largely used as an 

 external coating for candles on account of its 

 high melting point (160 F.). 



Psychic Development of Cats and Dogs. 



Prof. Wesley Mills's experiments on the 

 psychic development of young animals con- 

 tinue to be very interesting. In the kitten, 

 while the first stages are very slow and ob- 

 scure, the author finds that in the progress 

 of all the senses to full development the 

 course, while marked by definite steps, is 

 often so rapid that distinct advances may 



be marked in a single day. Apart from 

 the senses, etc., there seems to be a definite 

 order in which all the features of feline na- 

 ture appear, as, for instance, purring, crouch- 

 ing, stalking, etc. Certain physical changes 

 are correlated in time with certain psychic 

 developments, the significance of which is 

 in some cases clear, in others obscure. Com- 

 paring the two animals, the cat, on the whole, 

 develops more rapidly than the dog, the 

 greatest difference between them appearing 

 in the social and gregarious nature of the 

 dog and the independent and solitary traits 

 of the cat. The dog is docile in the highest 

 degree ; the cat to a slight degree, compared 

 with its intelligence. The play instinct is 

 early and highly developed in both, and the 

 peculiar qualities of each are well exhibited 

 in the manifestation of it. In will power 

 and ability to maintain a separate existence 

 the cat is superior to the dog. In the higher 

 grades of intelligence the wisest dogs are 

 much in advance of the most knowing cats ; 

 and this is foreshadowed if not exemplified 

 in the early months of existence. The na- 

 ture of the dog as compared with the cat 

 tends to beget prejudices in his favor with 

 the mass of persons, so that in general the 

 dog is overestimated and the cat underesti- 

 mated with the great majority ; at the same 

 time the dog's nature is much nearer that of 

 man than the cat's. u The kitten may amuse, 

 but even a puppy dog touches chords of sym- 

 pathy in the heart of man that the cat can 

 never reach." 



An Incandescent Oil Lamp. Ever since 

 the successful introduction of the incandes- 

 cent mantle in gas lamps, inventors have 

 been hard at work trying to construct an oil 

 lamp which could be used to replace the gas 

 in heating the mantle. Many such lamps 

 have been contrived, but up to the present 

 time none of them have proved satisfactory. 

 It is now announced, however, in Industries 

 and Iron, that such an oil lamp having an 

 atmospheric burner has recently been offered 

 for inspection in London, which seems to be 

 free from most of the defects of its prede- 

 cessors, and which promises to become a 

 great commercial success. It is called the 

 " Era " incandescent petroleum burner, and 

 consists of a " gallery burner," spreader, 

 mantle, and chimney in fact, everything 



