DELIVERED AT HAZELWOOD AND BRUCE CASTLE. 85 



tendon to remedy, when called upon to repeat the Lectures. 

 Some of these imperfections were necessarily consequent upon 

 the novelty and recent introduction of the entire department, 

 as a branch of the business of the Schools, and the inexpe- 

 rience, in this particular respect, of all the parties engaged. 

 And it must be added, that many minutiae, philosophically 

 important, and to which it would be requisite carefully to at- 

 tend, in the instruction of more advanced Students, must 

 necessarily be disregarded, in a seminary for the general edu- 

 cation of Boys. 



The following is a Syllabus of a Course of Lectures on the 

 Supporters of Combustion and the Simple Combustible Sub- 

 stances, comprehending part of what is called Pneumatic Che- 

 mistry, or the Chemistry of the Gases, which was delivered to 

 the three Upper Classes of boys, at Bruce Castle, in the 

 Spring of 1830. The extracts which are occasionally intro- 

 duced, as well as those occurring in the next Syllabus, may 

 be taken as specimens of the manner in which the young audi- 

 tors were addressed. The Lectures were given, in the last 

 hour of school, every day, excepting Saturdays and Sundays, 

 until the completion of each course. 



Two Introductory Lectures were delivered on the nature 

 and objects of Chemical Science, and the subjects stated above 

 were then entered-upon in the following order. The ancient 

 and long-prevailing opinion that atmospheric air was an ele- 

 mentary substance having been noticed, it was proposed expe- 

 rimentally to examine this opinion, with relation, especially, 

 to the property possessed by the air of sustaining combustion. 

 It was shown, by the combustion of phosphorus in a confined 

 portion of atmospheric air, that it must consist of two very 

 different gases or species of air ; one of which allowed the phos- 

 phorus to burn, while the other manifestly extinguished it. 

 These gases were then named, Oxygen and Azote, and the 

 proportions, 21 of the former and 79 of the latter, by bulk, in 

 which they are mingled to constitute the air, were stated, and 

 shown in a diagram. The effects of heating lead and mercury 

 in the air for a considerable time, in the absorption of the 

 oxygen and the leaving the azote free, were described, and 

 the oxides of those metals so produced, red-lead^ and red ox- 

 ide of mercury^ exhibited to the classes. It was next stated 

 that since these oxides would give out, if more strongly heated, 

 the gas the oxygen which they had thus absorbed from the 

 air, we might examine the properties of that gaseous substance 

 in a pure state, free from the azote with which it is mingled 

 in the air. The oxide of manganese^ it was then observed, 

 bearing the same relation to the metal manganese^ that oxide 



