Introduction.

The liquid would remain at the same temperature. Take another smaller vessel made of thin sheet copper or tin plate, fill it with water, oil, or any other liquid, and immerse it in the larger vessel of water for a certain time. Then, if we use our thermometer to record the temperatures of the liquids in the two vessels both before and after the immersion of the copper vessel, we find the following: if they are originally at the same temperature, the temperature of both remains the same. However, if one is at a higher temperature than the other, the one with the higher temperature becomes colder and the one with the lower temperature becomes hotter. If they continue in contact for a sufficient time, they eventually arrive at the same temperature, after which no further change of temperature takes place.

The loss of temperature by the hot body is not generally equal to the gain of temperature by the cold body This refers to the fact that different materials have different "specific heat capacities," meaning one degree of cooling in one substance might provide enough energy to raise another substance by several degrees., but it is manifest that the two simultaneous phenomena are due to one cause. This cause may be described as the passage of Heat from the hot body to the cold one.

As this is the first time we have used the word Heat, let us examine what we mean by it.

We find the cooling of a hot body and the heating of a cold body happening simultaneously as parts of the same phenomenon, and we describe this phenomenon as the passage of heat from the hot body to the cold one. Heat, then, is something which may be transferred from one body to another, so as to diminish the quantity of heat in the first and increase that in the second by the same amount. When heat is communicated to a body, the temperature of the body is generally increased, but sometimes other effects are produced, such as a change of state original: "change of state"; this refers to physical transitions such as ice melting into water or water boiling into steam.. When heat leaves a body, there is either a fall of temperature or a change of state. If no heat enters or leaves a body, and if no changes of state or mechanical actions take place within the body, the temperature of the body will remain constant.

temperature — The degree of hotness or coldness of a body.
thermometer — An instrument used to measure temperature.
immersion — The act of dipping or submerging something into a liquid.
Heat — A form of energy transferred between bodies due to a temperature difference.
change of state — A physical transformation from one phase of matter to another, such as solid to liquid or liquid to gas.