AMU 



AM1J 



loured flume, and, if the heat he- 

 enough, melts, and emits a pec' ilu. p 

 able ixlour, and leaves little aslu s. When 

 rubbed, k acquires a strong nep-athc e!< <- 

 tricul virtue. From this property is de- 

 rived the word electricity. It is com- 

 posed of carbon, hydrogen, and oxygen. 

 Amber is often found in the alluvial de- 

 posit (usually called Marie) of New-Jer- 

 sey. According to Sir .1. Hill, it is said 

 that amber has been found in digging in- 

 to the alluvial land in the vicinity of Lon- 

 don. It is found sometimes on the sea- 

 shores of several parts of England. Being 

 susceptible of a fine polish, it is cut into 

 necklaces, bracelets, snuff-boxes, and 

 other articles of dress. Before the discove- 

 ry of the diamond and other pi- 

 stones of India, it v :as considered tube the 

 most precious of jewels, and was employ- 

 ed in all kinds of ornamental dress : altars 

 were likewise ornamented with it. The 

 greatest quantity at present consumed in 

 commerce is purchased by Armenian and 

 Grecian merchants, for the use, it is con- 

 jectured, of pilgrims, previously to their 

 journey to Mecca, and that on their ar- 

 rival there it is burnt in honour of the pro- 

 phet Mahomet. The acid and oil obtain- 

 ed from it are used as medicines. 



If often contains insects of various spe- 

 cies, in a state of complete preservation, 

 also leaves, and other parts of vegetables. 

 Various conjectures have been made re- 

 sp< ct'.ng its origin and formation. By 

 some it is, as we have already seen, con- 

 sidered as a vegetable gum or resin ; 

 others regard it as a mineral oil, thicken- 

 ed by the absorption of oxygen; and Mr. 

 Parkinson is of opinion, that it is in 

 ted mineral oil. There was lately found 

 in Prussia a massof amber which weighed 

 upwards of 13 pounds, the contents of 

 which amounted to 318? cubic inches. 

 Five thousand dollars are said to have 

 been offered for it ; and the Armenian 

 merchants assert, that in Constantinople 

 it would sell for six times that price at 

 least. Pitch-coal is sometimes found with 

 amber, and is called black, and is sold 

 to the ignorant at a great price. Spe- 

 cimens inclosing insects, &c. are highly 

 valued, and the amber-dealers are said to 

 be possessed of means of softening it, in 

 order to introduce insects and other fo- 

 reign bodies into it. Two parts of the 

 cmpyreumatic oil obtained by distilling 

 mineral pitch boiled several times, with 

 three parts of turpentine, form a com- 

 pound, which b.-arsa great resemblance 

 to amber, and which is often cut into 

 necklaces and other ornaments, and sold 

 as true amber. 



AMMKRtiK'IS, in chemistry, is a sub- 

 stance found floating on the sea, near the, 

 coasts of India, Africa, and Brazil, usual- 

 ly in small pieces, but sometimes in mass- 

 es of 50 or 100 pounds in weight. Vari- 

 ous opinions have been entertained con- 

 cerning its origin. Some affirmed that it 

 was the concrete juice t>f a tree ; others 

 thought it a bitumen ; but it is now esta- 

 blished, that it is a concretion, formed in 

 tlie stomach or intestines of the physeter 

 maci-ocephulus, or spermaceti whale. Am- 

 bergris, when pure, is a light soft sub- 

 stance which swims on water. Its speci- 

 fic gravity varies from 0.78 to 0.844. Its 

 colour is ash-grey, with brownish yellow 

 and white streaks. It has an agreeable 

 smell, which improves by keeping. Its 

 taste is insipid. When heated to 122, it 

 melts without frothing ; if the heat be in- 

 creased to 212, it is volatilized completely 

 in a white smoke, leaving only a trace of 

 charcoal. Whendistilled, we obtain a whi- 

 tish acid liquid and a light volatile oil ; a 

 bulky charcoal remains behind. It is in- 

 soluble in water. Acids have little action 

 on it Weak sulphuric acid occasions no 

 change ; but, when concentrated, it de- 

 velopes a little charcoal. Nitric acid dis- 

 solves it, giving out at the same time ni- 

 trous gas, carbonic acid, and azotic gas. 

 Afbrownish liquid is formed, which leaves, 

 when evaporated to dry ness, a brittle 

 brown substance, possessing the proper- 

 ties of a resin. The alkalies dissolve it by 

 the assistance of heat, and form a soap 

 soluble in water. Both the fixed and vola- 

 tile oils dissolve ambergris. It is soluble 

 also in ether and alcohol. It possesses the 

 properties of the salty matter into which 

 the muscles are converted by nitric acid, 

 and which makes its appearance when 

 dead bodies are allowed to putrefy in great 

 numbers together. This substance has 

 been distinguished by the name of adipo- 

 cire, from its resemblance both to fat and 

 wax. The quantity of it in ambergris, 

 amounts to 52.8 parts. According to the 

 analysis of ambergris made by Bouillon 

 La Grange, it is composed of 



52.7 adipocire 



30.8 resin 



11.1 benzoic acid 

 5.4 charcoal 



1.000 



AMBIDEXTER, a peson who can use 

 both hands with the same facility, and for 

 the same purposes, that the generality of 

 people do their rght hands. 



Were it not for education, some think 



