Correspondeace of Bishop Milner in the Gentleman's Maga- zinf. LX,234. 332, 412; OLnER. Collections Illustrating History (rf the Catholic Religion in Comicall. 565; Cooper in Diet. .Vu(. Biog., II. 224; Gii-Low, Bibr. Dirt. Ena. Cnih.. T. S4.
J. H. Pollen.
Atkinson, S.ui.^^h, philanthropist and biographer, b. at AtUone, Ireland, 13 October, 1823; d. Dublin, 8 July, 1893. She was the eldest daughter of John and Anne Gaj-nor, who Uved on the western bank of the Shannon, in that part of Atlilone which is in the Coimty Roscommon. At the age of fifteen, she removed "with her family to DubUn, where her education was completed. At twenty-five, she mar- ried Dr. George .\tkinson, part proprietor of the "Freeman's Journal". The loss of her only child in his fourth year so deeply affected ilrs. Atkinson that she resolved to spend the rest of her life in chari- table and other good works. With her friend. Mrs. Ellen Woodlock. she interested herself in the female paupers of the South DubUn Union, and opened a home to which many were transferred and were made useful members of society. Her house in Drum- condra soon became the rendezvous for the charitably disposed. It was even more a literary salon. Here she prepared her life of Man,' Aikenhead which Mr. W. E. H. Leckj' has warmly commended, and here she wrote her many valuable essays. For many years she translated into EngUsh the French ". Annals of the Propagation of the Faith ". Much of her time was devoted to \-isiting the hospitals and poor people at their homes, and to other beneficent pur- poses. To her is largely due the success of the Cliildrens' Hospital, Temple Street, Dublin. The management of the SodaUty of the Children of Marj-, attached to the Church of St. Francis Xavier, was one of her particular pleasures. To the Hospice for the Djang. at Harold's Cross, she was a constant bene- factress. Even her writings were made to serve the great objects of her Ufe. In Duffy's "Hibernian Magazine", 1860-64, "The Month", 186-1-65, "The Nation", 1869-70, the "Freeman's Journal", 1871, and in the " Irish Monthly " after its inception are to be found many important essays by her, chiefly biographical and" historical. Some of her earliest and longest essays appeared in the " Irish Quarterly Review "; the best of them are included in her volume of "Essays" (Dublin, 1895). Her "Life of Mary Aikenhead", modestly published with her initial onlv, appeared in 1879, and is one of the best Catholic bio'graphies in Enghsh. Her " Es-says" include com- plete and learned dissertations on such divergent subjects as "St. Fursev's Life and Visions", "The Geraldines", "The Dlttamondo ", " Devorgilla ", " Eugene O'Currj' ", " Irish Wool and Woolens ", " St. Bridget ", and e"xcellent biographies of the sculptors John Henry Foley and John Hogan, the best accounts yet written of those great artists. Indeed most of these essays are the best studies we have on the vari- ous subje'cts. Her "Qtizen Saint" (St. Cathenne of Siena; occupies a htmdred pages, and is a most able summarj'.
McLBOLL.t.ND, in the Freeman's Journal files (Uublin, July, 1893), and prefatorj- memoir in ibe Essays; TlN.tN. Irish Independent, 61e3 (DubUn, July, 1893); The Irish Monthly (Dublin, November, 1893)— a full list of her wntmgs.
D. J. O'DOXOGHCE.
Atkinson, Tho-mas, Ven. martj-red at York, 11 March, 1616. He was b. in the East Riding of Yorkshire, was ordained priest at Reims, and returned to his native countrj- in 1588. We are told that he was unwearied in \-isiting his flock, especially the poor, and became so well known that he could not safely travel by day. He always went afoot imtil, ha%-ing broken his leg. he had to ride a horse. .\t the age of seventy he was be- trayed, and carried to York with liis host, Mr. Vava.sour of Willitoft, and some members of the family. A pair of beads, and the form of an in-
diJgence were foimd upon him, and he was con- demned to be hanged, drawn, and quartered. He suffered "with wonderful patience, courage, and constancy, and signs of great comfort ".
Cn.u.LOXEH, Missionary Priests, II, 51; Gillow, Bibl. Diet, of Engl. CaOi., I, 86.
Atom. — (Gr. a privative, and T4ij.va, cut; indi\nsi- ble). Primarily, the smallest particle of matter wliich can exist; the idtimate and smallest di\-ision of matter; in physics, sometimes the smallest par- ticle to which a substance can theoretically be re- duced; in chemistrj', the smallest particle of matter that can exist in combination w-ith other atoms building up or constituting molecules. Two opposite doctrines of the constitution of matter were held by the ancient philosophers. One was that matter was infinitely di\-isible -without losing its distinctive and indi\-idual properties. This is the doctrine of continuity or homceomerj'. Anaxagoras is given as the founcler of this view of the constitution of things. According to it any substance, such as wood or water, can by no process of subdivision, however far it might be carried, be made to be anything but a mass of wood or water. Infinite subdivision would not reach its limit of di\nsibihty. Democritus and others held that there were ultimate particles of matter which were indivisible, and these were called atoms. This is the doctrine of atomicity, upheld by Epicurus, and enlarged on by Lucretius in his " De Rerum Xatura". The early atomists held that the atoms were not in contact, but that voids existed between them, claiming that otherwise motion would be impossible. Among the modems, Descartes and Spinoza adhered to continuity, Leibnitz upheld atomicity, and Boscovich went to the last extreme of the theorj', and defined atoms as centres of force, denying them the attribute of impenetrabihty.
MoLECfLE .VXD -Atom. — Modern science holds that matter is not infinitely divi-sible; that there is an ultimate particle of everj- substance. If this particle is broken up. that particular form of matter w-ill be destroyed. This particle is the molecule. It is composed of another division of matter called the atom. Generally, probably always, a molecule consists of several atoms. The atoms unite to form molecules and cannot exist except as constituents of molecules. If a molecule of any substance were broken up, the substance would cea.se to exist and its constituent atoms would go to form or to enter into some other molecule or molecules. There is a tendency to consider the molecule of modern science as identical with the atom of the old philosophers; but the modern atomic theorj- has given the mole- cule a different status from that of the old-time atom. Atom, as used in natural science, has a specific meaning based upon the theorj- of chemistry. This meaning is modified bj- recent work in the field of radio-activitj-, but the following will .serve as a defini- tion. It is the smallest particle of an element which can exist in a compound. An atom cannot exist alone as such. Atoms combine with each other to form molecules. The molecule is the smallest particle of matter which can exist without losing its distinctive properties. It corresponds prettj- closelj- to the old Epicurean atom. The modern atom is an entirely new- conception. Chemistrj- teaches that the thousands of forms of matter upon the earth, almost infinite in varietj-, can be resolved into about eightj' substances, unalterable by chemical processes and possessing definite spectra. These substances, are called elements. The nietaLs. iron, gold, silver, and others, sulphur, and carbon are familiar examples of elements. A mass cf an element is made up of a collection of molecules. Each molecule of an ele- ment as a rule is composed of two atoms. Elements combine to form compound substances of various