MEDICAL CHEMISTRY. PART I. INTRODUCTION. 1. DEFINITIONS.-Science is a systematic and orderly arrangement of knowledge. It is founded upon observation and experiment. A theory is a deduction from established facts, and occupies a prominent place in science. A hypothesis is a supposition brought forward to explain facts or phenomena. Natural science treats of the external appearance and internal structure of natural objects. Examples: Botany, zoölogy, and mineralogy deal with the classification and structure of plants, animals and minerals respectively, and are, therefore, natural sciences. Physical science treats of the properties and phenomena of the matter of which these bodies are composed. Matter is anything whose existence is revealed to us by our senses. The properties of a body are the peculiar qualities by which it makes itself known to us; as color, solidity, odor, taste, etc. Physics is that branch of physical science which treats of the phenomena presented to us by bodies or masses of matter as such. Chemistry is that branch of physical science which treats of the ultimate composition of bodies, and the changes which this composition may undergo. Physics teaches us that water is hot or cold; that it may exist as steam, liquid water, or solid ice. Chemistry tells us that it is composed of two gases called hydrogen and oxygen, in the proportion of two of the former to one of the latter, by volume, and one of the former to eight of the latter, by weight. It also teaches us how we can prove this to be true. Matter exhibits certain properties which are common to all bodies, and which are therefore called the general properties of |