enumerates the divers other manufactures which would be created by the repeal of those laws, and proceeds in a forcible manner to show the baneful effects which they have had upon those great nurseries of our seamen, the fisheries of Great Britain. In February, 1819, he first published his "Letter to Farmers and Graziers on the use of Salt in Agriculture," in which he details the methods of its advantageous application as a manure, in feeding cattle, in preserving hay, in the destruction of worms and insects, and even in rearing bees; he also inserts copious extracts from the evidence given on the subject of the Salt Laws before the Board of Trade, in April, 1817, and before a Select Committee of the House of Commons, in April, 1818, on both of which occasions he was examined at great length for many days; and the united testimony of the most celebrated agriculturists and men of science of whom England could boast, went to prove the inestimable advantages that would accrue to the country from the repeal of those laws.

The interest that was excited on the subject by this book, and the consequent rapidity of its sale, were probably unprecedented. The first edition, published on the 22nd of February, sold off instantaneously; the second came out in March, the third on the 1st of May, and the fourth on the 1st of November of the same year. The late Sir Thomas Bernard was a fellow-labourer with him throughout this question, and gave his time and attention assiduously to it. At length, after twenty-eight years of unwearied exertion, during a considerable portion of which period little hope had appeared of ultimately obtaining any beneficial result, Mr. Parkes had the satisfaction of seeing his labours crowned with success by the total repeal of the laws in 1825, since which time the increased consumption of salt has fully justified his statements, and proved the correctness of his anticipations.

Engaged, as Mr. Parkes was, in the management and superintendance of an extensive chemical manufactory, which required unremitting attention and the greatest portion of his time, his works were composed at those hours which would generally be devoted to amusement or repose; but such was the unwearied and indefatigable nature of his mind, that,

besides his books, which demanded his constant care in preparing for new editions, in altering and adapting them to the perpetually-improving state of the science, and his papers for the periodical publications, which were all composed with more than ordinary pains, (as, for instance, the last paper which he ever wrote " On the analysis of some Roman Coins," published in the Quarterly Journal for July, 1826, during the composition of which he submitted to accurate analysis upwards of twenty coins, costing him the incessant labour of many months, as he made it an invariable rule never to place dependance upon any experiment till it had been repeated, and the same result again obtained)-besides all these avocations, which appear amply sufficient to fill up the time of one man, he kept a regular diary of every action of his life, and from an early age till within a few months of his death, never once retired to rest until he had committed to writing all the events of the day. He had common-place books, in which he entered everything worthy of note, whether gathered from reading, observation, or conversation, and he never performed a single chemical experiment without registering every particular of the process and the result. By these means he had always a mass of information collected upon most scientific subjects, and no improvement or valuable fact, once known, could ever be lost or forgotten, but, if it related particularly to chemistry, was sure, if useful, to appear in the next edition of the Catechism. As if all these occupations were insufficient to give full employment to his hours, his beautiful collections of Greek and Roman coins, prints, autographs, minerals, and fossils, were constantly and rapidly increasing, and, as fast as collected, were arranged in the most methodical manner.

On several important trials, Mr. Parkes was a very material witness; and where the question at issue hinged on a chemical point, as was so peculiarly the case in that between Messrs. Severn, King, and Co. and the Insurance Offices, he never hesitated to give up his time and attention for weeks and months in studying the subject, and in trying the requisite experiments with precision and accuracy. In the year 1818, Mr. Parkes was applied to by Messrs. Turner, Woodhead, and Co., of Rotherham, upon whom seizures had been made by

the Board of Excise of British gum which had been prepared in their starch-manufactory, upon the pretence of its being brown starch that had not paid duty; the penalties sued for amounted to upwards of 3000l. Samples were sent to him for analysis, on a careful examination of which he found that they possessed none of the properties of starch; and when the cause came on to be tried in the Court of Exchequer, in which he was subpoenaed as an evidence for the defendants, having obtained permission to repeat in court the experiments by which he had ascertained the points in which British gum differs from starch, the proofs were considered to be so decisive, especially the one of the beautiful blue precipitate produced by the solution of iodine, that a verdict was immediately pronounced for the defendants.

It is truly wonderful that one man should be capable of doing all that he did; that, actively engaged in business as he was for so many years, he should be able to write so much, and yet be always prepared to follow with ardour any scientific investigation, or chemical analysis, that might present itself. In experiments he was delicate and sure, never disheartened by failure or by the tediousness of the operations, and rarely stated any fact in his books till he had previously verified it himself.

The Chemical Catechism was the work to which its author was the most fondly devoted; it was his first production; it was the foundation on which his reputation as a chemist had been raised: twenty years had not lessened the attachment of the public to it, and the unusually large editions which he published were called for with even more rapidity at last than they had been at first. The Rudiments of Chemistry, and the Chemical Essays, had both been received with unequivocal marks of approval,-each had passed through large editions, and been quickly sold; the essays had been translated into various languages, and both had been republished in different parts of the United States: but the Catechism was, as it were, identified with his very name, it bore all the characteristics of his powerful and original mind; to bring it nearer to perfection had been his most assiduous labour, his most cherished pleasure, for twenty years. The perusal of the Cate

chism had induced the principal literary societies of both hemispheres to present him with their diplomas, and to elect him one of their members: the Government of Spain had ordered it to be used in the schools and colleges; and, in testimony of his approbation of it, the Autocrat of the Russias presented its author with a splendid and valuable ring.

The preparation of the twelfth edition for the press was the last avocation of its author. Although his body had for months been fast sinking beneath the constant attacks of a long and painful disease, which the foreboding fears of his friends too truly predicted must at length terminate fatally, yet his mind, unwearied and indefatigable as ever, preserving in full force its characteristic activity and diligence, was sedulously employed in the revision and improvement of its favourite production. The same anxiety to collect and insert all newlydiscovered facts, all recent improvements in the science to which he had so long devoted his time and energies; the same ardour of research, and attentive examination of every source whence he expected to derive useful information, were possessed by him during the performance of this last work as they ever had been whilst in the full enjoyment of bodily health, nay, existed in full force till within a few days of that fatal moment when the scientific world was for ever deprived of his talents and acquirements, and his friends were left to deplore the loss of an affectionate relative, a sincere friend, and interesting companion.

For several years preceding his death he had been collecting and arranging materials for a work, the composition of which he had long contemplated. He entitled it, "A History of the Discoveries in the several branches of Natural Philosophy, Astronomy, and Chemistry; including an account of the introduction of the various kinds of chemical apparatus, and the invention of all philosophical, nautical, and astronomical instruments, from the beginning of the Christian æra to the present time, affording a general view of the progress of Science and Literature during that period." It is to be regretted that he did not live to complete it, as such a subject in his hands must have proved a valuable acquisition to those who delight in tracing the gradual but regular advances of knowledge.

Many other essays, on different subjects, which he never published, attest the varied nature of his acquirements.

In June, 1825, Mr. Parkes, whose health had been for some months past slowly declining, was taken ill at Edinburgh, and brought to London by easy stages. All that could be done by the most eminent physicians was done; but the disease was too deeply rooted to be eradicated, and his family had the pain of watching him fast sinking away from his sphere of usefulness. Throughout the whole of his acute and severe sufferings, he was never heard to repine, but always expressed the most lively pleasure at receiving the visits of his numerous friends; and the last sentence he uttered was to thank a gentleman for his kindness in coming to see him. His friends, however, only alleviated his pain, and after a severe struggle he closed his active life on the 23rd of December, 1825.

Mr. Parkes was a man of an inquiring and unwearied mind, persevering and ardent in the pursuit of knowledge, and happy in his mode of imparting it to others. Not a moment of his day was ever suffered to pass unemployed: after writing upon one subject for a long series of hours he retired from his study, not from the slightest feeling of fatigue, but because the time for his meals, or for rest, was arrived. Whatever subject he was perusing, he neyer abandoned it till he had fully accomplished his object, and till every source of information was exhausted. By turns he had attended to almost every department of literature, and of general science, indeed was well versed in them; but natural philosophy, and more particularly the chemical branch of it, was his favourite pursuit, and engrossed most of his attention. His well-stored library afforded him every facility of reference, and he bestowed much pains on its selection and arrangement.

Probably no author ever attracted so many students to the science on which he was treating, as Mr. Parkes did to the study of chemistry by the publication of the catechism: the easy familiarity of its style, the happy knack which he possessed of rendering the driest and otherwise most unattractive parts inviting and pleasing, by interspersing them with useful and interesting matter not immediately connected with his subject, added to the admirable system of arrangement, adapted