1 N S 



INSCRIPTION, a tide, or writing affixed to any 

 thing, to give foiue fartlier knowledge thereof ; or to tranf- 

 niit lonie important truth to pofterity. 



Antiqv'.aries are very curious in examining ancient in- 

 fcriptions found on tloiies, and otlier monuments of anti- 

 quity. Sanchoniathon, contemporary, as it is faid, with 

 Gideon, drew moll of t!ie memoirs whereof his hiftory is 

 compofed from infcriptions which he found in temples, 

 and on columns, both axnong the heathens and the He- 

 brews. 



It appears, indeed, that the ancients engraved upon pillars 

 the pruiciples of iciences, as well as the hillory of the world. 

 Thofe mentioned by Herodotus (hew, that this was the firil 

 way of indrufting people, and of tranfmitting hillories, 

 and fciences, to polierily. This is confirmed by Plato in 

 his Hippias, wlicrein he fays, that Pififtratus engraved, on 

 ftone pillars, precepts ufeful for huftandmen. Pliny af- 

 fures us, that the firit public monuments were made of plates 

 of lead ; and that the treaties of confederacy concluded 

 between the Romans and tlie Jews were written upon plates 

 ©f brais ; that, fays he, the Jews might have fomething to 

 put them in mind of the peace and confederacy concluded 

 with the Romans. The Greeks and Romans were much 

 addidled to infcriptions, and were extremely fond of being 

 mentioned in them : and hence it is that we find fo many in 

 thofe countries of ancient learning, that large volumes have 

 been compofed ; as the collcftion of Gruter, &c. ' 



Since Gruter's collcdion, Th. Reinefius has compiled 

 another huge volume of infcriptions. M. Fabretty publifhcd 

 another volume at Rome in 1 669, wherein he has corrected 

 abundance of errors which had efcaped Gruter, Reinefius, 

 and other antiquaries, &c. and added a great number of in- 

 fcriptions omitted by them. Since all thefe, Graevius has 

 p ..blifhed a complete collection of infcriptions, in three vo- 

 lumes folio. 



Ikscription', Academy of. See Academy. 



Inscriptions, Notes, or Abbreviations, ufedin. See Cha- 

 racter. 



INSCRUTABLE,UKSF.ARCHABLE,inr/rfO%_)',isnfually 



imderftood of the fecrets of Providence, and the judgments 

 of God, which cannot be found out, or into which human 

 reafon cannot penetrate. 



INSE, in Geography, a town of Pruflia ; 22 miles \V. of 

 Tilfit. 



INSECTS. See Entomology. 



Insects, Anatomy of. Many parts of this fubjecl have 

 been already confidered in the article Entomoloc;y, to 

 which we refer the reader : our prefcnt object is to fupply 

 what has not been inferted there. 



Organs of Motion. — A itriking difference is obferved in the 

 pofition oi the hard parts, which conftitute the elTcntial or- 

 gans of motion, between this clafs and the mammalia, 

 birds, &c. In the latter, the bones are placed in the centre 

 of tlic limbs, and are furrounded by the mufcles, which are 

 covered externally by the Hvin ; while in the former, the re- 

 fifUng matters, which are analogous to bones and perform 

 their functions, are hollow, placed externally, fupply the 

 place of ikin, and contain the moving powers in their 

 cavities. 



The llrufture and appearances of the external coverings 

 vary confiderably in the different orders of this clafs. In the 

 crab, loblter. Sec. a hard calcareous cruft covers the whole 

 body and limbs, ferving for Ikin and Ikeleton. In the per- 

 fect infects thefurface of the body n covered by horny fub- 

 llances of various degrees of hardncfs and refinance. The 

 larvf have co\-crings of a fofter kind, and approaching more 

 nearly, as far as external characters go, to the flcia of mam. 



I N S 



malia and of the neighbouring clafTes. Yet this is anal'^; 

 in its functions to the calcareous and horny crufls ; t 

 receives the infertion of the mufcles, and therefore c'>. 

 tutcs the chief agent of locomotion. 



The fenfible cliaradters of the calcareous cruft of 

 crab and loblter (their Jhcll as it is commonly ca!': 

 rcfemble thofe of the fhells of teftaceous animals, and ; 

 fomc degree thofe of bone : but the chemical conftitutioii 

 is in fome refpefts different. The very valuable refearc' '.": 

 of Mr. Hatchett have m.ade us acquainted with the c' 

 circumftances of the compofition of thefe matter^. A 

 having detailed his experiments on fhells and on the c.v 

 ings of the echini, he proceeds : " It was now requifil. ^ 

 afcertain if phofphate of hme is a component part of ti.i^ 

 fiibllauce which covers the crullaceous marine or aqiia.x 

 animals, fuch as the crab, loblter, prawn, and era)-!!';:. 

 Pieces of this fubftance, taken from various parts of t' 

 animals, were at different times immerfed in acetous and 

 luted nitric acid ; thofe which had been placed in the di! : 

 nitric acid produced a moderate effervefcence, and in a fr ' 

 time were found to be foft and elaftic, of a yellowifh-white 

 colour, and hke a cartilage, which retained the original 

 figure. The fame effects were produced by acetous acid, but 

 in a lefs degree ; in the latter cafe alfo the colouring matter 

 remained, and was foluble in alcohol. AU the {olutions, 

 both acetous and nitric, afforded carbonate and phofphate of 

 lime, though the former in a larger proportion. There is 

 reafon to conclude, therefore, that phofphate of hme, mingled 

 with the carbonate, is a chemical characteriftic, which dil- 

 tinguiflies the crullaceous from the tellaceous fubllances ; 

 and that the principal difference in the qualities of eacli, 

 when complete, is caufed by the proportion of the hardening 

 fubftances, relative to the gluten, by which they are ce- 

 mented ; or by the abundance and confiitency of the gelati- 

 nous, membranaceous, or cartilaginous fubltance, in and on 

 which the carbonate of lime, or the mixture of the car- 

 bonate and phofphate, has been fecreted and depofited. And 

 as the prefence of phofphate of lime, mingled with carbo- 

 nate, appears to be a chemical character of cruftaceous ma- 

 rine animals, there is every reafon to conclude that Linnaeus 

 did right not to place the echini among the teftaceous ones. 

 The prefence of phofphate of lime, in the fubftance which 

 covers the crullaceous marine animals, appears to denote an 

 approximation to the nature of bone, which, not only by the 

 experiments of Mr. Gahn, but by the united tellimony of all 

 chemills, has been proved principally to confift, as far as tlie 

 ollifying fubftance is concerned, of phofphate of lime.'' 

 Philof Tranf. 1799. In a recapitulation of thefe re- 

 fearches, in the Tranfattions for 1800, he fays, " it was 

 proved, that the cruft which covers certain marine animals, 

 inch as crabs, lobfters, cray-fifh, and prawns, confifts of a 

 ftrong cartilage, hardened by a mixture of carbonate and 

 phofphate of lime ; and that thus thefe cruftaceous bodies 

 occupy a middle place between fhell and bone, though they 

 inchne principally to the nature of Ihell." Similar refults to 

 thefe were obtained by Merat-Guillot, who has defcribed 

 his inveftigation in the Annales de Chimie, t. 34. From 100 

 parts of lobfter cruft, he obtained 60 of carbonate of hme, 

 14 of phofpliato, and 26 of animal matter. In 100 parts of 

 cray.filh cruft there were 60 of carbonate, 12 of phofphate, 

 and 26 of animal matter. So far as the horny coverings of 

 infects have been examined, they correfpond in chemical 

 properties to horn, hoof, fcales of ferpents, feathers, &c. 

 and do not owe their firmnefs to calcareous matter, which 

 feems not to be an elTential part in their formation. See 

 Horn. 



An intcrefting enquiry arifes here, concerning the mode 



