A. Yes. _All_ bodies contain heat; the coldest ice, as well as the hottest fire. Q. _Is there HEAT even in ICE?_ A. Yes. But it is _latent_, (i. e. not perceptible to our senses).[4] [4] Latent, from the Latin word, Lateo, (to lie hid.) Q. _How do you know there is heat, if you cannot perceive it?_ A. Thus:--Ice is 32° by the thermometer; but if ice be _melted_ over a fire, (though 140° of heat are thus absorbed,) it will feel no _hotter_ than it was before. (_i. e. it will be only 32°, and not 172°_)[5]. [5] 32°, i. e. 32 degrees; 140°, i. e. 140 degrees, &c. Q. _What becomes of the 140°, which went into the ice to melt it?_ A. It is hidden in the water; or (to speak more scientifically) it is stored up in a _latent state_. Q. _How much heat may be thus secreted or made latent?_ A. _All_ things contain a vast quantity of latent heat; but, as much as 1140° of heat may remain latent in _water_. Q. _How can 1140° of heat be added to water, without being perceptible to our feelings?_ A. 1st--140° of heat are hidden in the water, when ice is melted by the sun or fire. 2ndly--1000° more of heat are secreted, when water is converted into steam. Thus, before ice is converted into steam, 1140° of heat become _latent_.[6] [6] Thus, one pint of boiling water, (212° according to the thermometer,) will make 1800 pints of steam; but the steam is no hotter to the touch than boiling water, both are 212°: therefore, when water is converted into steam, 1000° of heat become latent. Hence, before ice is converted to steam, it must contain 1140° of latent heat. Q. _Can we be made to FEEL the heat of ICE or snow?_ A. Yes. Into a pint of snow put half as much salt; then plunge your hand into the liquid; and it will feel so intensely cold, that the snow itself will seem quite _warm_ in comparison to it. Q. _Is SALT and SNOW really COLDER than snow?_ A. Yes, many degrees; and by dipping your hand into the mixture _first_, and into snow _afterwards_, the mere snow will seem to be comparatively warm. Q. _What is FIRE?_ A. Combustion is another instance of heat, arising from chemical action. Q. _What two things are essential to produce combustion?_ A. Fuel and air. Q. _What are the elements of fuel?_ A. As bread is a compound of flour, yeast, and salt; so fuel is a compound of hydrogen and carbon. Q. _What are the ELEMENTS of atmospheric AIR?_ A. The air is a compound of oxygen and nitrogen _mixed_ together; in the proportion of five gallons of nitrogen, to one of oxygen. Q. _What is CARBON?_ A. The solid part of fuel. It abounds also in all animal bodies, earths, and minerals. Q. _Mention some different SPECIES of CARBON._ A. Common charcoal, lamp-black, coke, black lead, and the diamond, are all varieties of carbon. Q. _What is HYDROGEN?_ A. An inflammable gas. The gas used in our streets, is only the hydrogen gas _driven out of coals by heat_. Q. _What are the peculiar characteristics of hydrogen gas?_