1813.] 



Scientific Intelligence, 



507 



was found to exhibit the same phenomena to a limited extent } 

 but no other substance tried. 



We have still some other discoveries, made by Dr. Brewster^ 

 on light, to mention ; but this article has already extended to 

 such a length that we must delay our account pf them till our 

 next number. 



III. Matches that takejire when dipped into sulphuric acid^ 



In answer to our Weymouth correspondent^ who requests us 

 to inform him what is the composition of these matches, we. 

 answer, that such matches are by no means new ; they have been 

 known for many years to chemists. They are composed of the 

 hyperoxymuriate of potash in powder, mixed with sugar or 

 charcoal powder. The whole must be well mixed together. But 

 whoever makes thera must beware of rubbing them hard in a 

 mortar, for such a mixture is apt to explode. There is no occa- 

 sion for much nicety about the proportions. I have often made 

 such matches, eight or ten years ago, and then employed equal 

 Weights of the two ingredients. 



rV. Popuhtlm of Sunderland, 



A correspondent from Sunderland has obliged us with a por- 

 rection of our statement of the population of that town in our 

 last number. It consists, he says, of three parishes united, 

 namely, Sunderland, Bishopwearmouth, and Monkwearmouth ; 

 and the population of all the three, which constitutes the town 

 of Sunderland, exceeds, he says, 30,000. We have not the 

 parliamentary returns for 1811 at hand; but have no doubt of 

 the accuracy of our correspondent. 



V. Geognosy of Werner, 



In our last number we inserted an admirable paper by Pro- 

 fessor Jameson of Edinburgh, vindicating the geognosy of 

 Werner from the attack made upon it by the Edinburgh Review. 

 Professor Jameson maintained, against the opinion of the re- 

 viewer, that Cuvier and Brogniard, in their account of the envi- 

 rons of Paris, had adopted the conclusions, and used the lan- 

 guage, of the Wernerian geognosy. Had he seen the Recherches 

 sur les Ossemens fossiles de Quadrupeds, published by Cuvier in 

 1812, he would have found the following passage, which deserves 

 to be quoted as a vindication, or rather demonstration, of Pro- 

 fessor Jameson's opinion : — ' En efFet, la partie purement mine- 

 ' rale du grand probleme de la theorie de la terre a ete etudiee 

 avec un soin admirable par de Saussure, et portee depuis a un 

 developement etonnant par M. Werner et par les nombreux et 

 savaos eleves qu'il a formes.— Le second (Werner) profitant des 

 nombreuses excavations faites dans le pays da monde ou sont le« 



'¥2 



