1819.] Scientific Intelligence. 153 



XIV. Vaccination in Denmark. 



For the last eight years not a single case of small-pox has 

 occurred in the dominions of the King of Denmark. The whole 

 inhabitants have been vaccinated. Here is one good effect 

 which has resulted from the arbitrary power of the King of Den- 

 mark. Between 1752 and 1762 the small-pox carried off in 

 Copenhagen alone 2644 victims; from 1762 to 1772, it carried 

 off 2116 ; from 1772 to 1782, 2233 ; from 1782 to 1792, 2735; 

 but from the introduction of vaccination in 1802 to the end of 

 1818 only 158 persons have died of the small-pox; namely, 

 1802, 73 ; 1803,5; 1804, 13; 1805, 5 ; 1806, 5; 1807,2; 1808, 

 46; 1809, 5; 1810, 4; 1811,0; 1812,0; 1813, 0; 1814, 0: 

 1815,0; 1816,0; 1817,0; 1818,0. 



XV. New Instrument. 



Mr. Perkins, of Philadelphia (whom the newspapers have 

 announced as on his passage to England, in order to submit to 

 the Directors of the Bank of England a specimen of bank bills 

 which defy forgery), has invented an instrument, called the 

 Bathometer ; which is intended to show, by the compressibility 

 and elasticity of water, the depth of the sea. He is said to have 

 produced a pressure of water in a confined column equal to that 

 of more than 200 atmospheres, or upwards of '3000 pounds to every 

 square inch of surf ace ; being equal to the pressure of 6,400 feet 

 in fresh water. Mr. Perkins intends to prepare a graduated 

 scale, showing the exact degree in which water is actually com- 

 pressible. 



XVI. Death of Professor Play fair. 



John Playfair, Esq. F.H.S. Lond. andEdinb. &c. Professor of 

 Natural Philosophy in the University of Edinburgh, died on 

 Tuesday, July 20, at his house in Forth-street, Edinburgh. He 

 was the son of Dr. James Playfair, author of a System of Chro- 

 nology of great reputation. The Professor was supposed to be 

 the principal conductor of the scientific department of the Edin- 

 burgh Review. The works which he has left behind him are I 

 Elements of Geometry, 8vo. 1796; second edition, 1804 ; Illus- 

 tration of the Huttonian Theory of the Earth, 1802 ; a Letter to 

 the Author of the Examination of Professor Stewart's Statement, 

 8vo. 1806; a Complete System of Geography, Ancient and 

 Modern ; and detached papers in various periodical publications. 



ERRATUM in the present Number. 

 Page 90, line 28, for 5-917, read 64367. 



