CHEMICAL COMPOSITION OF THE SAP. 123 



contain water, volatile matter, acetate of potash, carbonate of lime, 

 vegetable matter, sulphate of potash. 



Sap of the beech, (Fagus sylvatica,) contains water, acetate of 

 lime, with excess of acid, acetate of potash, gallic acid, tannin, mu- 

 cous extract, acetate of alumine. 



Sap of the Horse-chestnut, (^sculds hippocastamm,) contains wa- 

 ter, extractive mucous matter, nitre, acetate of potash, and carbon- 

 ate of lime.* 



These few examples of the decomposition of vegetable principles 

 show how wide a field is open to the chemist, in the study of vegeta- 

 ble elements. 



It may seem wonderful, that of so few elementary substances, 

 such a great variety should exist in the taste, smell, colour, consist- 

 ence, medicinal and nutritious qualities of vegetable combinations ; 

 is it not equally wonderful that with the nine digits and the cij^her, 

 we may make such varied combinations of numbers ; or witli our 

 twenty-six letters of the alphabet, form every variety of composi- 

 tion ? Thus, by various combinations of a few simple principles, are 

 formed all vegetable and animal productions. 



The presence of nitrogen was formerly considered as a test of 

 animal substance, and the want of it of a vegetable substance, but 

 it is now ascertained that animal substances may exist without nitro- 

 gen, and that this principle is contained in several vegetables. 



The elements of the compounds being the same, the question natu- 

 rally arises, what causes the great diversity in the properties 7 Two 

 causes maybe assigned for this; viz. 1st. The different proportions 

 in which the elements are combined. 2d. The various modes of their 

 combination. 



In vinegar and sugar, the one substance a liquid, and of a sour 

 taste, the other solid and sweet, are found the same elements in dif- 

 ferent proportions and differently combined. In gum, starch, and 

 sugar, the elements are the same, the proportion nearly the same, but 

 they are combined differently. 



When we know by chemical analysis the combinations which ex- 

 ist in inorganized bodies, we can, by putting the same together, often 

 form similar substances ; but we cannot thus form organized bodies ; 

 for to these belongs a living principle, which it is not in the power 

 of man to bestow. It is said, that Rousseau, skeptical in science as 

 in religion, declared he would not believe in the correctness of the 

 analysis of vegetable or animal substances, until he should see a 

 young animal, or a thrifty plant, spring into existence from the retort 

 of the chemist. But the power to create, the Almighty has not dele- 

 gated to man ; neither is it to be supposed that any future discov- 

 eries in science will ever confer it upon him. To study the com- 

 pound nature of substances, to classify, arrange, and by various com- 

 binations to beautify the world of matter, to cultivate the faculties 

 of mind, until stronger and brighter the mental vision sees facts and 

 principles before invisible ; these are the high privileges bestowed 

 on man ; — but to add one new particle to matter, or one new faculty to 

 the mind, is beyond the power of the whole human race. 



* These results of the analysis of sap are extracted from Vauquelin. 



Sapofthebeech— Of the horse-chestnut—All vegetable and animal productions com- 

 posed of a few simple principles— Illustration— What two causes assigned for the dif- 

 ferent properties of compounds formed from the same elements ?— Organized bodies 

 not produced by the skill of man. 



