136 Dr. Cuthush on the Chinese Fire, fyc. 



M. Bigot has given an improved formula for the same 

 purpose, viz. 



He has also given a particular composition, in vk^hich 

 antimony is added in lieu of iron. It consists of 



Salt-petre, - - - 16 parts. . 



Sulphur, - - _ . 4 do. 



Charcoal, - - - - 9 do. 



' Antimony, (crude) - - 2 do. 



It was not our intention to have noticed at this time the 

 war or incendiary rockets, and particularly the so called 

 Congreve rockets ; but as the composition of the Congreve 

 rocket is supposed to differ from the ordinary kind in many 

 essential particulars, the analysis which we subjoin, refutes 

 such an opinion. 



General de Grave transmitted to Paris, a Congreve 

 rocket, found on the French coast. The case was made of 

 grey paper and painted. The larger sort are usually made 

 of sheet iron. 



The inflammable matter was of a yellowish grey colour^ 

 and the sulphur was distinguished with the naked eye. It 

 burnt with a quick flame, and exhaled sulphurous acid gas. 

 The examination was made by Gay Lussac. According to 

 his analysis {Archives des Decouvertes, ii, 303.) the com- 

 position is 



Nitrate of potash, _ - - 75.00 

 Charcoal, - - - - - 1.6 

 Sulphur, - - - - - 23.4 



100. 

 Gay Lussac, after determining the proportions, made a 

 composition of a sinylar kind, and charged a case with it, 

 which had the same properties as the English rocket. The 

 proportion of charcoal is too small. 



