486 R E S R E S blood differs from arterial blood chiefly in the relative amounts of O and CO 2 it contains. Which of these substances is it whose deviation from the arterial standard causes stimulation? It so happens that we can experi- mentally separate the two factors. If an animal be placed in a chamber of some inert gas, such as nitrogen, the escape of CO., from the lungs is unimpeded and no accumu- lation of CO 2 in the blood is brought about ; nevertheless dyspnoea and asphyxia follow as if the entrance of air to the windpipe had been interrupted. Here there is no accumulation of C(X in the blood, but total deficiency of O. On the other hand, if an animal be placed in a chamber containing a large excess of CO 2 beyond the standard of expired air, but at the same time a superabundant supply of O, no dyspnoea supervenes, and no asphyxia threatens. The animal may suffer from drowsiness (for CO 2 is narcotic in its effects), but true dyspnoea never occurs so long as the supply of O is sufficient. There is little doubt there- fore that the absence of from venous blood is the essen- tial condition of its stimulating property. Diversity of Modes in which the Function is Carried en. Kespiration, if we assume the essential fact of that process to be the absorption of O and the elimination of CO 2 by the animal body, is coextensive with the whole animal kingdom. It is not, however, in every case served by special air-containing organs or lungs. Indeed the essential interchange of respiration goes on wherever the blood comes into sufficiently close contact with oxygen. For example, the air which happens to be swallowed with our food is so closely in contact with the blood of the intestinal vessels that an interchange of gases occurs, con- stituting a true intestinal respiration. The Mammalia all possess true lungs. In birds also there are lungs, but the mechanism of respiration is unlike that of man, since the diaphragm is wanting. There are, in birds, besides lungs, " air sacs " lying among the viscera and communicating with cavities in the bones, these sacs being supplied with air from the lungs. Reptiles and some amphibians breathe by lungs, other amphibians breathe by gills, as also do the young of some of the air-breathing Amphibia (frogs). Fishes breathe by gills, using the O dissolved in water. Many invertebrates respire in air, which is carried into the midst of their tissues in tracheae or air-tubes branched like a tree ; other invertebrates breathe by gills in water ; others again have lungs. In some the oxygenized water is carried into the body along a series of tubes the water-vascular system ; and in still simpler animals the general surface of the body seems to serve the respiratory function. (A. G.*) RESTIF, NICOLAS EDME (1734-1806), called RESTIF DE LA BRETONNE (the form RETIF, though occasionally used by the author himself, and adopted by M. Monselet, has the less authority), was born at Sacy in the present department of the Yonne, France, on 23d October 1734. His father was a farmer of not the lowest rank, and the vanity of Restif has preserved or invented an extraordinary genealogy (supposed to date from his grandfather's time) in which the family is traced to the Roman emperor Pertinax. This Restif did not take very seriously, but he is himself almost the only authority for the details of his own career, which he has voluminously recorded, and these details are in part so incredible, in part so obviously dis- torted by various motives, that it is very hard to do more than discover the general outline of his life. He was well educated partly if not chiefly by his own devotion to books he was apprenticed to a printer at Auxerre, and, having served his time, went to Paris. Here he worked as a journeyman printer for some time (indeed he con- tinued his manual work for the greater part of his life), and in 1760 he married Anne or Agnes Lebegue, a relation of his former master at Auxerre. He soon tired of her, and has left the most unfavourable pictures of her morals and temper. In the early years of their married life they were but little together, and for the last twenty they never saw each other; but Restif 's own account is sufficient to show that certainly not all, and pro- bably very few, of the faults were on the wife's side. It was not till five or six years after his marriage that Restif, who by his own account had written voluminously from his earliest youth but had published nothing, appeared as an author, and from that time to his death on February 2, 1806, he produced a bewildering multitude of books (amounting to something like two hundred volumes, and many of them printed with his own hand) on almost every conceivable variety of subject. The most noteworthy are Le Pied de Fanchette, a novel (1769) ; Le Pornographe (same date), a plan for regulating prostitution which is said to have been actually carried out by the emperor Joseph IL, while not a few detached hints have been adopted by Continental nations; Le Paysan Perverti (1774), a novel in which much of his own experience is worked in ; La Vie de Mon Pere (1779), a really remarkable monu- ment of filial piety; Les Contemporaines (42 vols., 1780-85), a vast collection of short stories showing at once Restif's fertility of invention, his narrative faculty, and his accurate observation of the manners of Paris ; Ingenue Saxancom also a novel (1789) ; and, lastly, the extraordinary autobio- graphy of Monsieur Nicolas (16 vols., 1794-97; the last two are practically a separate and much less interesting work), in which at the age of sixty he has set down voluminously his remembrances, his notions on ethical and social points, his hatreds, and above all his numerous or innumerable loves real and fancied. The original editions of these, and indeed of all his books, have long been bibliographical curiosities owing to their rarity, the beautiful and curious illustrations which many of them contain, and the quaint typographic system in which most are composed. The author's life during this long period was a singular mixture of hard work and perpetual falling in love. He seems to have really seen society of the most varied kind, though in this as in all other matters he certainly exaggerates and perhaps invents in a way which makes it impossible to dis- cern the exact truth. Some of his books sold well, and, as has been said, he was always industrious as an author or a printer and sometimes as both. But he had repeated losses, and though never in actual want was never in easy circumstances. He was arrested once during the Revolu- tion but had no difficulty in getting off; indeed he seems to have been a convinced republican. In 1795 he received a gratuity of 2000 francs from the Government, and just before his death Napoleon gave him a place in the ministry of police, which he did not live to take up. After his death Cubieres Palmeaux, a gentleman literary-hack of the day, wrote his life. Restif do la Bretonne undoubtedly holds a remarkable place in French literature, though the rarity and curious character of his books have sometimes induced his editors and commentators to take too high a view of his merits. He was inordinately vain, of extremely relaxed morals, and perhaps not entirely sane. His books were written with such haste and in such bulk that they can only be praised with great allowance. Their licence of subject and language renders some if not most of them quite unfit for general perusal. But when every deduction is made there will remain on a just estimate the facts that Restif had a singular and profound knowledge of the human heart 'the second title of his Monsieur
