I'KKI'ACE ix 



Thus the desire to direct those thirsting for truth to the pure 

 source of the science of the forces acting throughout nature forms 



of the science, but also the generally-accepted deductions, and also hypotheses, 

 which refer to phenomena as yet but imperfectly known. In this latter sense 

 scientific contemplation varies much with times and persons, it bears the stamp 

 of creative power, and comprehends the highest branch of scientific progress. 

 In that pure enjoyment experienced on approaching to the ideal, in that eagerness 

 to draw aside the veil from the hidden truth, and even in that discord which 

 exists between the various workers, we ought to see the surest pledges of further 

 scientific success. Science thus advances, discovering new truths, and at the 

 same time obtaining practical results. The edifice of science not only requires 

 material but also a plan, and necessitates the work of preparing the materials, 

 putting them together, working out the plans and the symmetrical proportions 

 of the various parts. To conceive, understand, and grasp the whole symmetry of 

 the scientific edifice, including its unfinished portions, is equivalent to tasting 

 that enjoyment only conveyed by the highest forms of beauty and truth. Without 

 the material, the plan alone is but a castle in the air, a mere possibility, whilst 

 the material without a plan is but useless matter ; all depends on the concordance 

 of the materials with the plan and execution, and the general harmony thereby 

 attained, In the work of science, the artisan, architect, and creator are very 

 often one and the same individual, but sometimes, as in other walks of life, 

 there is a difference between them ; sometimes the plan is preconceived, some- 

 times it follows the preparation and accumulation of the raw material. Free 

 access to the edifice of science is not only allowed to those who devised the plan, 

 worked out the detailed drawings, prepared the materials, or piled up the brick- 

 work, but also to all those who are desirous of making a close acquaintance with 

 the plan, and wish to avoid dwelling in the vaults or in the garrets where the 

 useless lumber is stored. 



Knowing how contented, free, and joyful is life in the realms of science, one 

 fervently wishes that many would enter their portals. On this account many 

 pages of this treatise are unwittingly stamped with the earnest desire that the 

 habits of chemical contemplation which I have endeavoured to instil into the 

 minds of my readers will incite them to the further study of science. Science 

 will then flourish in them and by them, on a fuller acquaintance not only with 

 that little which is enclosed within the narrow limits of my work, but with the 

 further learning which they must imbibe in order to make themselves masters of 

 our science and partakers in its further advancement. 



Those who enlist in the cause of science have no reason to fear when they 

 remember the urgent need for practical workers in the spheres of agriculture, 

 arts, and manufacture. By summoning adherents to the work of theoretical 

 chemistry, I am confident that I call them to a most useful labour, to the 

 habit of dealing correctly with nature and its laws, and to the possibility of 

 becoming truly practical men. In order to become actual chemists, it is 

 necessary for beginners to be well and closely acquainted with three impor- 

 tant branches of chemistry analytical, organic, and theoretical. That part of 

 chemistry which is dealt with in this treatise is only the ground work of the edifice. 

 For the learning and development of chemistry in its truest and fullest sense, 

 be.iri nners ought, in the first place, to turn their attention to the practical work of 

 analytical chemistry: in the second place, to practical and theoretical urquaiut- 



