586 PHILOSOPHICAL TRANSACTIONS. rANIfO 1795. 



naceous matter was dissolved by the gaz, but I think. I shall prove, that no such 

 combitiation takes place; and I now consider it to be most probable, that the di- 

 munition arises from the dissolution of the last portions of adhering iron. 



With respect to the quantities and nature of the gaz separated in this ex- 

 periment: 1. The quantity of it from each 100 grs. of wootz, on trials at dif- 

 ferent times, was found to be from 78 to 84 oz. measures: the mean quantity 

 was therefore 8 1 . 2. The gaz from each 100 grs. of steel wire, after many 

 trials, was found to be from 83 to 86 oz. measures: the mean quantity was 

 therefore 84 L. 3. The gaz from each 100 grs. of bright iron wire, by many 

 trials with the same and different parcels of wire, was found to be from 86 to 

 88 oz. measures: the mean quantity therefore was 87. 



It is to be understood, that when the quantities of the different parcels of 

 gaz were compared with each other, they were measured at the same tempera- 

 ture, and under the same degree of pressure. It is also to be understood, that 

 whenever the solutions of wootz, steel, and iron, were made at the same time, 

 and under the same circumstances as far as known, there was uniformly a smaller 

 bulk of gaz from wootz than from steel, and from steel than from iron. The 

 smell of the gaz from the above 3 substances was that of hydrogen gaz : but I 

 thought that from wootz had a stronger and more offensive smell than from 

 steel; and that from steel was more offensive than from iron. I could perceive 

 no difference in the kind of flame, and explosion, between these 3 parcels of 

 hydrogen gaz; they burned in the same manner as common hydrogen gaz from 

 sulphuric acid, iron, and water. 



Portions of the above gazes mixed with oxygen gaz, from oxide of manganese, 

 were burned in close vessels by the electric fire, over lime-water. I could per- 

 ceive no difference in the combustion between the gazes from the above different 

 substances, nor any difference in the gaz from the same substance at different 

 stages of the dissolution. I did not perceive the lime-water to be at all disturbed 

 in its transparency on my first trials; but in subsequent ones, on viewing it more 

 attentively, and in a good light, it was perceived to be very slightly turbid. It 

 was equally so with all the parcels of gaz. To satisfy myself further, at the 

 time I made these experiments I exploded the mixture of inflammable gaz, ob- 

 tained my decompounding water with white hot charcoal of wood, with oxygen 

 gaz; by which the lime-water was rendered quite milky. This inflammable gaz 

 burnt very slowly, affording a deep blue lambent flame. 



To determine the quantity, and ascertain the nature, of the undissolved black, 

 matter in this experiment, I poured the solutions, while boiling hot, on filtres 

 of 3 folds of paper, and freed the filtres from the adhering solutions by pouring 

 boiling water on them. The paper was stained black by the solutions of wootz 

 and steel, as far as the liquid reached, but the paper was only stained black at 



