448 Analyses of Books. [Dec. 



second's pendulum at St. Helena, lat. 15° 55' S. is 39-04255 

 inches ; for Dr. Maskelyne found the length of the pendulum at 

 Greenwich to that at St. Helena as 10-0246 to 10. 



V. On the Length of the French Metre estimated in Parts of 



the English Standard. By Capt. Kater, F.R.S The result of 



a very careful measurement by Capt. Kater is, that the length of 

 the metre is 39-37079 inches of Sir George Shuckburoh's stan- 

 dard scale. 



VI. A few Facts relative to the colouring Matters of some Vege- 

 tables. 'By James Smithson, Esq. F.R.S. — The author refutes 

 an assertion of Fourcroy that turnsol is essentially of a red 

 colour, and that it contains carbonate of soda. The infusion of 

 turnsol contains no alkali, lime, nor acid, and its natural colour is 

 blue. When the colouring matter of turnsol is burned, it leaves 

 a saline matter which, with nitric acid, forms nitrate of potash. 

 Mr. Smithson suspects that this colouring matter, like ulmin, is 

 a compound of a vegetable substance and potash. The paper 

 contains experiments on the colouring matter of the violet, sugar- 

 loaf paper, the black mulberry, the com poppy, sap-green, and 

 some animal greens ; but they are of so unconnected a kind that 

 they are scarcely susceptible of abridgement. We must, there- 

 fore, refer our readers to the paper itself. 



VII. Account of Experiments made on the Strength of Mate- 

 rials. By George Rennie, Jun. Esq. — These experiments differ 

 a good deal from others of a similar kind given by former expe- 

 rimenters. Mr. Rennie found a cubical inch of the following 

 bodies crushed by the following weights : 



lbs. av. 



Elm. 1284 



American pine 1606 



White deal 1928 



English oak 3860 



Ditto of five inches long slipped with 2572 



Ditto of four inches ditto 5147 



A prism of Portland stone two inches long 805 



Ditto statuary marble 3216 



Craig Leith stone 8688 



Cubes of li inch. 



Sp. gr. 



Chalk — 



Brick of a pale red colour 2-085 



Roe stone, Gloucestershire , — 



Red brick, mean of two trials 2-168 



Yellow face baked Hammersmith paviors7 



three times 3 



Burnt ditto, mean of two trials , — 



Stourbridge, or fine brick — 



Derby grit, a red friable sandstone 2-316 



1127 

 1265 

 1449 



1817 



2254 



3243 

 3864 

 7070 



