76. With what metals is sulphur found in combination? 77. Why are milk and bread so necessary for the first food of an infant?

78. With what metals is phosphorus found in combination?

79. In what part of the animal kingdom does phosphorus chiefly abound?

80. What is the chief use of the sub-borate of soda? 81. What is the nature of Iodine, when was it first discovered, and how is it procured?

82. Is wood a simple or compound combustible? 83. Which are the supporters of combustion ?

84. Are supporters of combustion always supporters of life?

85. On what does the rapidity of combustion depend? 86. What is the philosophical effect produced on a fire by blowing?

87. Do the products of any combustion increase or decrease in weight?

88. What would be the weight of a fother of lead when converted into red lead?

89. Whence does the light come during combustion? 90. Is the product of combustion always an oxide? 91. If potassium or sodium be burnt, what will be its product?

92. What metal is that which has such affinity for oxygen, as to decompose water so rapidly as to ignite the hydrogen.

93. How is Potassium formed, and what are its peculiar qualities?

94. Has Sodium any peculiar affinity for oxygen? 95. How is soda obtained, and what are its uses? 96. Give the theory of burning a common candle. 97. Why is the top of the wick in common candles black when burning?

98. What angle of inclination must a candle have so as not to require snuffing?

99. What is Sir Richard Phillips's theory of Combustion? 100. Define Inflammation, Ignition, and Detonation or Explosion.

LIGHT.

101. What is Light?

102. What is the effect of the action of light on vegetables? 103. Why are the hearts of lettuces and other vegetables white, as also the bellies of fishes, and the inner feathers of birds, &c.?

104. What was the opinion of Sir Isaac Newton in regard to the nature of light?

105. What effect has the sun's rays when condensed and thrown on a delicate balance?

106. In what direction do the rays of light proceed?

107. Which rays of light from the sun that fall on our atmosphere undergo refraction, those that fall perpendicularly, or those that fall obliquely?

108. Required the velocity of light.

109. Through what cause is it that the heavenly bodies appear higher in the heavens than they actually are? 110. What is meant by a diaphanous body?

111. On what does the science of dioptrics depend? 112. When a ray of light passes from a dense into a rarer medium, how, or in what direction is it refracted? 113. In what direction is a ray of light refracted, when it passes from a rare into a denser medium?

114. When a ray of light falls upon a body and it does not become absorbed, what is the result?

115. What kind of bodies reflect light most?

116. On what does the quantity of reflected light depend?

117. To what is the angle of reflection always equal? 118. Which colour absorbs, and which reflects light the most?

119. What is that science termed which explains the doctrine of reflected light?

120. How are bodies seen?

121. What is meant by Vision?

122. Of what shape must the eye necessarily be?

123. What is that membrane of the eye termed on which objects seen become painted?

124.. Which are the humours of the eye, and explain them?

125. By what contrivance is the idea of the images of bodies seen conveyed to the brain?

126. If the object seen be delineated in an inverted position on the retina of the eye, how is it that it appears to us in its natural position?

127. As the object seen is painted on the retina of each eye, how is it that it does not appear double?

128. Of what particular shape is the eye of such persons as are near-sighted, and what kind of glass must they use to rectify their vision?

129. How does age generally affect the shape of the eye? 130. Which are the seven primary colours?

131. How is the idea of colour produced in our minds? 132. What is meant by the Spectrum?

133. How does Sir Richard Phillips explain colour? 134. If the spectrum be divided into 360 parts, what are the proportional parts for each colour?

135. The seven primary colours are reduceable to three; which are those three?

136. Which colour is most refrangible, and which least refrangible?

137. What is understood by homogeneous, and what by heterogeneous light?

138. Why does the sun appear of a red colour on a hazy morning?

138. From what does the whiteness and from what does the blackness of bodies arise?

139. What space of time would a ray of light take to travel from the sun to each planet individually; Mercury being 37 millions of miles distant, Venus 69 millions, the Earth 95 millions, Mars 144 millions, Jupiter 494 millions, Saturn 906 millions, and Georgium Sidus 1820 millions?

COLD.

140. What is Cold?

141. What effect has cold on bodies in general?

142. What is the highest degree of cold that has been produced artificially?

143. What simple mixture will cause the thermometer to sink suddenly from the freezing point to Zero?

144. In extreme cold, what is the consequence when the external air is suddenly admitted into a sitting-room 145. What is the usual effect of extreme cold on the system?

146. Under what circumstances, and when was it, that 7000 Swedes perished through extreme cold?

147. Relate the occurrence which took place at Terra del Fuego, during a botanical excursion of Sir Joseph Banks and others.

PNEUMATICS.

148. On what does the science of Pneumatics treat? 149. What are the component parts of the atmosphere ? 150. What figure does the atmosphere assume, through the motion of the earth and the action of the sun?

151. Is there any gas in the atmosphere, independent of its constituents, oxygen and azote?

152. What is the height of the atmosphere?

153. What is the whole weight of the atmosphere ? 154. What is the greatest height that an aeronaut has ascended?

155. How does air press?

156. What is, generally speaking, the greatest height of the clouds?

157. At what rate does the density of the atmosphere decrease?

158. What effect is produced on the system, at the tops of mountains, through the extreme rarity of the air? 159. At what rate, on every square inch of surface, does the air press?

160. Why will not the quicksilver rise higher than about 31 inches in a barometer?

161. Within what height from the earth do the sun's rays, in passing through the atmosphere, begin to suffer refraction?

162. Describe an easy experiment, showing the upward of the air?

pressure

163. What quantity of oxygen, or the pure part of air, does a man consume in an hour?

164. Why is it unwholesome to remain shut up in a newly plastered or whitewashed room?

165. Where is it that the air is so affected by exhalations of a coppery nature, as to tarnish the silver in the pocket?

166. What is the effect of heat on air?

167. What is the cause of Winds?

168. Describe an experiment, calculated to show the effect of heat in rarefying the air?

169. On what principle are fire-balloons made?

170. What would be the result if the air had no reflective power?

171. What is the cause of Twilight?

172. Describe Montgolfier's balloon?

173. What are the principal instruments used to show the various phenomena of the atmosphere ?

174. Why will water boil sooner on the top of a high mountain, than in a valley?

175. Where will water boil soonest, or with a less degree of heat, and why—at the bottom of a deep mine, or on the earth's surface?.

176. What is the use of the Air-pump; and by whom was it invented, and when ?

177. When a vessel has been partially exhausted by means of the Air-pump, through what principle is it that the remaining air fills the whole of the vessel ?

178. On what does the weight of bodies depend?

179. Will vegetation proceed in an exhausted receiver? 180. What effect is produced by the condensation of air?

181. Describe the Condensing Syringe.

182. On what principle does the Air-gun depend? 183. Why does the quicksilver fall in a Barometer when it is about to rain?

184. Describe the Barometer, and explain its principle. 185. For what other purpose is a Barometer used be