FRAGMENTS OF SCIENCE. 



75 



Hollows in the perpendicular wall faces of 

 the building are preferred, but any prox- 

 imity to the roof, where cats are liable to 

 abound, is shunned. The nooks furnished 

 in old houses advertised for sale or demoli- 

 tion, by the frames which are set upon them 

 for bill posting, are much resorted to by 

 the birds. The spaces between the frames 

 and the walls are commodious nesting places. 

 The under concavities of corrugated iron 

 roofing furnish hundreds of ready-made tun- 

 nels under the cross beams, and when one 

 of these roofs is built in a neighborhood, 

 the sparrows will desert their old, now less 

 attractive quarters "to a bird." "No cat 

 can climb it or stretch a claw far enough up 

 to hook out the nest." The London spar- 

 row is intensely local. " He moves as sel- 

 dom as he can from his own particular block 

 of houses or square or terrace ; and in the 

 suburbs he keeps not only to his own house, 

 but often to the back or front of the house 

 only, not caring to circumnavigate his own 

 suburban garden. In spring, when pulling 

 crocus flowers to pieces becomes a mania 

 with sparrows for a few days, it has been 

 noticed that in many instances all the spar- 

 rows in the front of the house will take a fit 

 of crocus-spoiling, while the flowers behind 

 the house are let alone. Or the reverse may 

 be the case, all those behind the house be- 

 ing spoiled, while the sparrows haunting the 

 front of the house and front garden are oc- 

 cupied in some other sphere of activity. If 

 an old nesting place is destroyed, the local 

 birds at once seek another as close as pos- 

 sible to it." 



Campbsr. Owing to the widespread use 

 of camphor in the arts and in medicine, its 

 increasing scarcity and expensiveness have 

 raised the problem of artificial cultivation. 

 There are a number of trees, many of them 

 widely separated in genus, order, or species, 

 from which camphor is obtained. The tree, 

 however, which produces most of the camphor 

 of commerce is the Cinnamomum camphora, 

 a member of the laurel family, belonging to 

 the tame genus as the cinnamon tree. This 

 tree attains enormous size. The bulk of the 

 camphor imported into Europe comes from 

 Japan and Formosa, and a small amount 

 from China, although the trees are very 

 abundant in the latter country, and the wood 



ismuchused. Every part of the tree is said to 

 be useful, even the fruit being employed in the 

 preparation of tallow. The statement that 

 the large use of smokeless powder is 

 sible for the high price of camphor is 

 by Sir Frederick Abel, who sayB that, while 

 camphor was much used in the manufacture 

 of smokeless powder in the early days, it was 

 soon shown to have serious practical disad- 

 vantages, and its use has been to a large 

 extent discontinued. It is, however, used 

 for the conversion of collodion cotton into 

 celluloid, and, in combination with various 

 ill-smelling compounds, is the basis of most 

 moth powders. In a recently published ac- 

 count of the commercial and scientific 

 value of this tree Dr. E. Grassmann urges 

 the importance of increasing the plantations 

 to the greatest possible extent, and the plac- 

 ing of some restriction on the wanton de- 

 struction of the trees. 



Evslstion tf the Storage Battery. A 

 recent article in the Journal of the Franklin 

 Institute, by Maurice Barnett, on the Evolu- 

 tion of the Storage Battery, gives many in- 

 teresting historical data. It seems that in 

 1801 Gauterot, while decomposing salt water 

 electrolytically, noticed that on breaking the 

 circuit he could obtain a current of short 

 duration from the electrodes. A few years 

 later Ritter constructed a pile consisting of 

 disks of copper, separated by pai 

 with saline solution ; after passing a 

 current through this pile he was able to ob- 

 tain a current of considerable intensity from 

 the pile itself. This was practically the first 

 storage battery. In 1859 Gaston Plante be- 

 gan a series of researches which led him 

 finally to the elaboration of a practical stor- 

 age battery. He electrolysed diluted sul- 

 phuric acid with rods of the various metals 

 used successively as electrodes. Lead gave 

 the most promising results, not only 00 ac- 

 count of its capacity, but also because of the 

 intensity of the discharge. Plante came to 

 the conclusion, in 1859, that lead was the 

 only useful metal, and then proceeded to 

 construct his spiral accumulator, which con- 

 sisted of two plates placed concentric with 

 each other in dilute sulphuric acid, one 

 plate being lead, the surface of which was 

 peroxidixed, the other, metallic lead. He 

 got from this electric couple an E. M. F. of 



