164 



DEFINITION OF TERMS. 



of the products afforded by oak bark, de- 

 duced by experiments conducted by my- 

 self. 



3S40 parts of ripe peas afford — 

 Of starch, - - - 1265 parts. 

 Fibrous matter analogous to 

 starch, with the coats of 

 the peas, ... 840 " 

 A substance analogous to glu- 

 ten, - - • - - 550 " 

 Mucilage, - - - 249 " 



Saccharine matter, - - 81 " 

 Albumen, - - - 66 " 



Volatile matter, - - 540 " 

 Earthy phosphates, - - 11 " 



Loss, - - - - 229 " 



1000 parts of dry oak bark, from a 

 small tree deprived of epidermis, con- 

 tain — 



Of woody fibre, - _ _ 876 

 tannin, - - _ - 57 



extract, _ - . . 31 



mucilage, - - - - 18 



matter rendered insoluble during 

 evaporation, probably a mixture 

 of albumen and extract, - 9 



loss, partly saline matter, - 30 



DEFINITION OF TERMS. 



Letter L 



Irnpelus, in mechanics, the force with 

 which one body impels or strikes an- 

 other. 



Incline Plane, in mechanics, one that 

 makes an oblique angle with the horizon. 



Incnrvation, of the rays of light, 

 their bending out of a rectilinear or 

 straight course, occasioned by refraction. 



Induction, in logic, a conclusion from 

 the particular to the general. Strict 

 conclusions are made from the general to 

 the particular. The general premise be- 

 ing true, the application to the particular 

 case which is included in it follows with 

 logical certainty. Induction gives only 

 probability. If, for instance, we conclude, 

 from the earth being habitable, that the 

 other planets are so, the conclusion is on- 

 ly probable. Induction rests upon the 

 belief that general laws and rules ar^ ex- 

 pressed in the particular case; but a pos- 

 sibility always remains that these gene- 

 ral laws and rules are not perfectly 

 known. An induction may be perfect 

 or imperfect. To make it perfect, the 



premises must include all the grounds 

 that can affect the result. If this is not 

 the case it is imperfect. For instance, 

 evei-y terrestrial animal lives, every serial 

 animal lives, every aquatic animal lives, 

 every reptile lives, therefore, every ani- 

 mal lives. If we now allow that there ex- 

 ists no animal not included in the four enu- 

 merated classes, the induction is perfect. 



Inertia of matter, in philosophy, is 

 defined by Sir Isaac Newton to be a pas- 

 sive principle, by which bodies persist 

 in their motion to rest, receive motion 

 in proportion to the force impressing it, 

 and resist as much as they are resist- 

 ed. It is also defined by the same 

 author to be a power implanted in all 

 matter, whereby it resists any change 

 endeavored to be made in its state. 



Inflection, or point of inflection, in 

 the higher geometry, is the point where 

 a curve begins to bend a contrary way. 



Infusion. — A method of obtaining the 

 virtues of plants, roots, &c., by steeping 

 them in a hot or cold liquid. 



Ink. — There are two principal kinds 

 of ink, writing and printing ink. 



Writing ink. — When to an infusion 

 of gall nuts some solution of sulphate of 

 iron (green copperas) is added, a very 

 dark blue precipitate takes place. This 

 principitate is the gallic acid of the galls 

 united to the iron of the green vitriol, 

 forming gallet of iron, which is the basis 

 of writing ink. If galls and sulphate of 

 iron only were used, the precipitate 

 would fall down, leaving the water co- 

 lorless; and in order to keep it suspended 

 in the water, forming a permanently 

 black, or rather a very dark blue fluid, 

 gum arable is added, which, by its viscid 

 nature, prevents the precipitate from 

 falling down. Various receipts have 

 been given for the composition of writing 

 ink, but very few have been founded 

 upon a knowledge of its real nature. 

 The receipt given by M. Ribencourt is 

 as follows: Take eight ounces of Aleppo 

 galls, in coarse powder; four ounces of 

 logwood in thin chips; four ounces of 

 sulphate of iron, (green copperas;) three 

 ounces of gum arable in powder; one 

 ounce of sulphate of copper, (blue vi- 

 triol;) and one ounce of sugar-candy. 

 Boil the galls and logwood together in 



