COMPARATIVE ZOOLOGY. 
CHAPTER I. 
MINERALS AND ORGANIZED BODIES DISTINGUISHED. 
Nature may be separated into two great kingdoms— 
that of mere dead matter, and that of matter under the 
influence of life. These differ in the following points: 
(1) Composition-—Iewer elements are used in the organic 
world than in the mineral. Over sixty are found in the 
latter, while four or five make up the former. Organic 
bodies have a striking uniformity of composition: the 
majority being ternary compounds, consisting of carbon, 
hydrogen, and oxygen; or quaternary, adding nitrogen ; 
while a few only contain also sulphur or iron. But min- 
erals exhibit a greater variety in their constitution, being 
made of one element alone, or two or more. In organic 
substances each ingredient is equally united with all the 
rest, while mineral compounds can be resolved into bi- 
nary combinations. Thus, fibrine, which is composed of 
carbon, hydrogen, oxygen, and nitrogen, is called a quater- 
nary compound; and carbonate of ammonia, made of the 
same materials, is considered a binary union of two other 
binary compounds, carbonic acid and ammonia. ut this 
distinction is shaken by the probability that binary princi- 
ples exist in living bodies. It is true, however, that the 
constitution of organic substances is more complex than 
that of minerals; for, though composed of few elements, 
