of the object of his employer in making the experiment, his simple and bare detail of facts will often be the best foundation for an opinion.  With respect to the higher qualities of intellect necessary for understanding and developing the general laws of the science, the same talents I believe are required as for making advancement in every other department of human knowledge; I need not be very minute.  The imagination must be active and brilliant in seeking analogies; yet entirely under the influence of the judgment in applying them.  The memory must be extensive and profound; rather, however, calling up general views of things than minute trains of thought.  The mind must not be, like an encyclopedia, a burthen of knowledge, but rather a critical dictionary which abounds in generalities, and points out where more minute information may be obtained.  In detailing the results of experiments and in giving them to the world, the chemical philosopher should adopt the simplest style and manner; he will avoid all ornaments as something injurious to his subject, and should bear in mind the saying of the first king of Great Britain respecting a sermon which was excellent in doctrine but overcharged with poetical allusions and figurative language, “that the tropes and metaphors of the speaker were like the brilliant wild flowers in a field of corn—­very pretty, but which did very much hurt the corn.”  In announcing even the greatest and most important discoveries, the true philosopher will communicate his details with modesty and reserve; he will rather be a useful servant of the public, bringing forth a light from under his cloak when it is needed in darkness, than a charlatan exhibiting fireworks and having a trumpeter to announce their magnificence.  I see you are smiling, and think what I am saying in bad taste; yet, notwithstanding, I will provoke your smiles still further by saying a word or two on his other moral qualities.  That he should be humble-minded, you will readily allow, and a diligent searcher after truth, and neither diverted from this great object by the love of transient glory or temporary popularity, looking rather to the opinion of ages than to that of a day, and seeking to be remembered and named rather in the epochas of historians than in the columns of newspaper writers or journalists.  He should resemble the modern geometricians in the greatness of his views and the profoundness of his researches, and the ancient alchemists in industry and piety.  I do not mean that he should affix written prayers and inscriptions of recommendations of his processes to Providence, as was the custom of Peter Wolfe, and who was alive in my early days, but his mind should always be awake to devotional feeling, and in contemplating the variety and the beauty of the external world, and developing its scientific wonders, he will always refer to that infinite wisdom through whose beneficence he is permitted to enjoy knowledge; and, in becoming wiser, he will become better, he will rise at once in the scale of intellectual and moral existence, his increased sagacity will be subservient to a more exalted faith, and in proportion as the veil becomes thinner through which he sees the causes of things he will admire more the brightness of the divine light by which they are rendered visible.