540 CONCLUSIONS. 



shattering effects produced by these substances. In order to 

 attenuate these effects it is well to dilute the bodies with an 

 inert matter ; this tends to change the detonation into a pro- 

 gressive combustion, a phenomenon of quite another character, 

 and in which mechanical actions are exercised more slowly; 

 this kind of combustion is the only one known with any 

 certainty in connection with black powder. 



Such are the general results of the comparison of different 

 explosive substances. In this work will be found the theoretical 

 volumes calculated for a great number of other mixtures ; but 

 in the above table we have limited ourselves to facts resulting 

 from experiments. 



7. Among the interesting conclusions which we have had 

 occasion to develop, attention may be called to the study of 

 the manifold decompositions of the same explosive substance, 

 such as ammonium nitrate ; the examination of the properties 

 of nitrogen chloride, of potassium and ammonium chlorate, and 

 of ammonium bichromate ; the decomposition of the nitro- 

 ethylic and nitro-methylic ethers ; the classification of the 

 various kinds of dynamite and the theoretical discussion of their 

 properties ; the study of gun-cotton properly so called, and that 

 of wet, paraffined, and " nitrated " gun-cotton ; the examination 

 of picrates, of mixtures formed with nitric acid, associated with 

 an organic matter, and the examination of perchloric ethers, and 

 lastly of oxalates. 



8. The study of powders with a nitrate base has led to 

 special developments, both practically and theoretically, owing 

 to the importance of this class of powders. 



The chemical reactions which take place between sulphur, 

 carbon, their oxides and their salts, have been carefully studied, 

 as also the decomposition of sulphites and of hyposulphites, 

 and the study of certain charcoals used in the manufacture of 

 gunpowder, and which retain an excess of the original energy 

 of the hydrocarbons from which they are derived. This excess 

 plays a very important part in the explosive properties of 

 gunpowder. 



Then the different mixtures of nitre, sulphur, and charcoal 

 which answer to total combustion were examined; the only 

 mixtures in which chemical reaction can be foreseen a priori. 



Service powders are first studied, taking the products of their 

 combustion such as are known by analysis. After having 

 summarised these analyses and carried them to the fundamental 

 products and to the equivalent relations, the fluctuations 

 observed between these relations are considered, and a theory 

 founded on the existence of five simultaneous equations is 

 established, in accordance with which the metamorphosis is 

 developed in a direction and relative proportion determined by 

 the local conditions of mixture and of inflammation. The 



