157 



CONSTELLATION. 



CONSTIPATION. 



158 



are comparatively faint. Other astronomers have since carried on the 

 lettering of Bayer, and we have latterly (in this work) distinguished 

 the letters added since Bayer's time by parentheses in all those con- 

 stellations which were partly lettered by Bayer and partly by others. 

 But in all cases the extent of Bayer's letters may be ascertained by 

 reference to the article in the Bioo. Div. headed by his name. The 

 letters had been adopted, however, previously to Bayer. [PiccoLOMlNi, 

 in BIOG. Div.] 



The next step in the arrangement was that of Flamsteed, who retained 

 the old method of describing stars by their situation in the figure of 

 the constellation (as in the leg, in the head, &c.), but placed the stars 

 of each constellation in order of right ascension, or in the order in 

 which they come on the meridian. Succeeding astronomers described 

 each star by the number which it stood from the beginning in the 

 constellation, and called it Flamsteed's number. Thus 7 Draconis 

 means that star of Draco which comes on the meridian the seventh of 

 all the stars observed by Flamsteed in that constellation. Mr. Baily, 

 in his new edition of the British Catalogue, introduced new stars 

 from Flamsteed's papers, but has allowed them to stand without dis- 

 turbing the established numbering, and they are easily identified by 

 the general numbering of the new catalogue. Thus, there is a star in 

 Capricornus between 12 Capr. and 13 Capr., which may be described 

 as 2786 of Mr. Baily's edition, that is, the 2786th from the equinox of 

 1690 of all the stars observed by Flamsteed, both of those which are 

 in the 'British Catalogue" of A.D. 1725, and those which have been 

 since drawn from Flamsteed's papers. 



The numbering of Piazzi is on a different and inferior principle. 

 The whole heavens being divided into twenty-four hours of right 

 ascension, the stars are numbered in their respective hours of right 

 ascension. For instance, (303) Can. Maj. is, according to Piazzi, a 

 star in Canis Major, not the 303rd of that constellation, but the 303rd 

 of the hour of right ascension in which it fell in the year 1800, count- 

 ing the first star of the catalogue which passed after the sidereal clock 

 had marked the hour as 1, the second star as 2, &c., and affixing to 

 each the name of the constellation in which it is. If the equinox were 

 fixed, this method would be a good first correction of the vagaries of 

 the constellations ; but as it is, some stars which were in one hour of 

 right ascension when Piazzi formed his catalogue are now in another, 

 such as 12 Cancri, 15 Argus, &c., which were in 1830 on the borders 

 of the 7-8 hour of right ascension. 



In most other catalogues, such as those of Bradley, Lacaille, Mayer, 

 Fallows, Ac., the stars are usually numbered in their order from the 

 beginning of the catalogue, the order being that of right ascension. 



The recognised makers of constellations are Aratus, Ptolemy, Bayer, 

 Hevelius, and Lacaille. But Tycho Brand, Lemonnier, and Poczobut 

 liave each added one constellation in the following list, and Halley two. 

 The names without any letter are all in Aratus. (Remember, however, 

 that Libra is only the clam of the Scorpion, both in Aratus and Pto- 

 lemy ) [LIBRA.] Three additional ones in Ptolemy's Catalogue are 

 denoted by P. : Bayer's by B. ; Hevelius's by H. ; Lacaille's by L. ; 

 Tycho BrahiS's by T. ; Halley's by Ha.; Lemonm'er's by Le. ; and 

 Poczobut's by Po. 



Andromeda. 



Antlia I'nt-umatica, L. 



Apparatus Sculptoris, L. 



A|JUS, B. 



Aquarius. 



Aquila. 



An. 



Argo, 



Aril*. 



Auriga. 



Bootei. 



Csclum 8calptorl>, I.. 



Caratlopardalis, II. 



Cancer. 



v.-nalici, II. 

 Cams Major. 

 Canl Minor, P. 

 Cipiicurnus. 

 Cassiopeia. 

 Cenuurus. 

 Cepheiu. 

 Cetas. 



ChannBlcon, B. 

 Circmu', L. 

 Cljrpetu Sobleski, II. 

 Columba. Ua. 

 Coma Berenices, T. 

 Corona Au-tralU, P. 

 Cciona Borealli. 

 Corriu. 



Crux, Ha, or by 

 Hover, from n.il- 

 ley'a observations. 



<' ."111.. 



Delphinas. 

 Dorado, B. 

 Draco. 

 Equulens, P. 

 Equuleus I'ictoris, L. 

 Eridaniu. 

 Fornax, L. 

 Oe nini. 

 Gnu, B. 

 Hercules. 

 H'irologium, L. 

 Hydra. 



Hvdru tt Crater.f 

 Ilidrun, B. 

 Indun, B. 

 Laceria, H. 



LOT. 



Lro Minor, H. 

 Lepui. 

 Libra. 

 Lupus. 

 Lynx, H. 

 Lyra. 



Microscopiura, L. 

 Monoceros, H. 

 Muca,+ B. 



Xorma, L. 



Oclam, L. 



O.ihiuchus. 



Orion. 



Pare, B. 



Pegasus. 



Perseus. 



Phenix, B. 



Pisces. 



Piscis Australia. 



Pi-cia Volann, B. 



Pixia Nautica, L. 



Reticulus, L. 



I . to >. 



Sag Harms. 



Scorpius. 



Bcrpeus. 



Sextans, H. 



8ol!tanu., Le. 



Taurus. 



Taurus Poniatowski, Po. 



Telescopium, L. 



Tiiangul* |j 



Triangulum Australe, B. 



Tucan, B. 



Ursa Major. 



Ursa .Minor. 



Virgo. 



Vulpecula (ot Anser), H. 



The Aris Indica of Barer. [Correct Apii Indica in BATKR, Bioo. Div.] 



t Crater i a separate constellation in I'tolemy. The neighbouring stars OB 

 the body of Hydra were considered by Flamstced as part of tills constellation. 



J 1 nis it the Apis of Bayer, called Musca by Lacaille ; there i, however, a 

 constellation lliuca, formed by Bod<>, we btlicvc, aud situated close to Aiics, 

 the stun of which are u-ually considered as belonging to Aries. 



} A piirt'.f Aqiiiln in Arulu. 



(| Only one in Aratm an 1 Ptolemy. Another adJcd by Ilcvelius. 



There are many other constellations formed by different individuals ; 

 but these are not now generally admitted. Such are the Antinous of 

 Tycho Brahe" ; the Mons Msenalus aud Cerberus of Hevelius ; the Oak 

 of Charles II. and the Cor Caroli of Halley; the Table Mountain and 

 the Nubecula Major and Minor of Lacaille (the latter being not clus- 

 ters of distinct stars, but large nebulae) ; the Reindeer of Lemonnier; 

 the Keaper of Latitude ; the Honours of Frederic, the Sceptre of Bran- 

 denburgh, Herschel's Telescope, the Balloon, the Mural Quadrant, the 

 Cat, and the Log Line of Bode ; and George's Harp of Hell. Many 

 others, we believe, have been proposed, but there would be little use 

 in reviving their names. In fact, half a century ago, no astronomer 

 seemed comfortable in his position till he had ornamented some 

 little cluster of stars of his own picking with a name of his own 

 making. 



In the large maps of the stars, published by the Society for the 

 Diffusion of Useful Knowledge, the constellations are figured precisely 

 as described by Ptolemy, and the additional ones are uot drawn, which 

 will therefore render them useful to the readers of Greek astronomical 

 works. 



CONSTIPATION, an undue retention or an imperfect evacuation 

 of the faeces. The alimentary canal, considered physiologically, may 

 be divided into two portions ; one appropriated to the conversion of 

 the aliment into nutriment, and the other appropriated, among other 

 functions, to the separation and discharge of the refuse matter of the 

 aliment. The first constitutes the apparatus of digestion, and the 

 second that of fsecation. Independently of the organs appropriated to 

 the performance of the preparatory operations of prehension, mastication, 

 insalivatiou, and deglutition, the apparatus proper to digestion consists 

 of the stomach, the duodenum or the second stomach, the jejunum, 

 and the ileuni, the three latter portions of the alimentary canal forming 

 the small intestines. It is in these great digestive chambers that the 

 processes of chymification and chylification are performed ; processes 

 by which the multifarious substances taken as food are converted into 

 an homogeneous substance analogous in its composition to the blood. 

 The requisite changes on the food are effected partly by secretions 

 formed by the walls of the digestive chambers themselves, aud partly 

 by secretions elaborated by distinct organs and conveyed into the 

 digestive chambers by separate tubes. These auxiliary organs are the 

 pancreas and the liver, the Quids secreted by which perform a most 

 important pai t in the function of digestion. The chyle, the ultimate 

 result of the action of these digestive fluids, is absorbed, as it is formed, 

 by a set of vessels termed the lacteals, spread out upon the walk 

 more especially of the jejunum and ileum, upon the surface of which 

 they take their origin by open mouths. 



But a considerable portion of the substances taken as food is in- 

 capable of being converted into chyle ; this is separated from the chyle 

 partly in the duodenum, and still more perfectly in the jejunum and 

 ileum, as it flows over the walls of these extended chamOers. More- 

 over, a considerable portion of the digestive Quids themselves does not 

 enter into the composition of the chyle, but is separated from it aud 

 mixed with the refuse matter of the food. .Again, the whole extent of 

 the alimentary canal, from its commencement to ita termination, is 

 lined with a membrane which secretes a peculiar fluid, termed mucus. 

 This fluid which defends the delicate and sensitive vessels that are 

 crowded on every point of the digestive chambers, and which maintains 

 those chambers in a state of suppleness and moisture, is constantly 

 formed, removed, and renewed. That portion of it which has served 

 its office, and which has become effete, is mixed with the refuse 

 matter of the aliment and of the digestive fluids. All these substances 

 mixed together in a common mass are transmitted to the second 

 portion of the alimentary canal, which consists of the large intestines ; 

 namely, the caecum, the colon, and the rectum, by the operation of 

 which the second part of the digestive function, that termed faocation, 

 is performed. This function consists of two processes ; first, of that 

 by which the common mass of excremeatitious substances is brought 

 into a state fit for its discharge from the body ; and secondly of that 

 by which a force is generated adequate to eiiect its discharge. The 

 chief agent by which these substances are brought into a state fit for 

 their discharge is the bile. [BiLE ; in NAT. HIST. Div.] The agent 

 by which their actual discharge is effected is the muscular coat of the 

 intestines, which is excited to contraction, and thereby to the generation 

 of the force requisite to the accomplishment of the object, by the 

 stimulus of the bile. 



It i.s obvious, then, that the matters to be discharged from the 

 alimentary canal do not consist, as is vulgarly supposed, merely of 

 the refuse portion of the food : this constitutes only a small part of 

 those matters; an essential part of it consists of the refuse matter 

 of secretions which have performed most important offices in the 

 economy. 



There is manifest in the performance of certain functions of the 

 body a tendency to periodicity. The most remarkable of these are the 

 return, at regular periods, of the necessity for sleep, of the appetite for 

 food, and of the command to remove from the body the excremeutitious 

 m ttters prepared in the alimentary canal. Whatever may have first 

 led to the formation of these habits, and however they may be varied 

 by circumstances which operate at an early period of life, they canaot, 

 after having been once formed, be materially and frequently interrupted 

 without danger to the health. The interruption of one of these habitn 



