83 



BENZOIN. 



BENZOLE. 



spontaneous produce of the tree during the first three years, is termed 

 head benzoin ; that obtained subsequently, belly benzoin ; and at the 

 end of ten or twelve years, the tree is cut down, the wood split up, 

 and the scrapings collected and termed foot benzoin. These different 

 sorts are of the relative value of 105, 45, 18. The benzoin which is 

 met with in commerce is generally in cakes or fragments of different 

 sizes, of a yellowish or fawn colour, covered with a whitish powder, 

 intermixed with pieces of wood or leaves. When broken it exhibits a 

 vitreous fracture, presenting portions of an almond-like shape, which 

 are whiter than the surrounding portions, transparent, and friable. 

 The more of these white pieces that occur in any specimen, the more 

 it is esteemed ; from exposure to the air they assume a yellowish hue. 

 An inferior kind, called benzoe in sortis, is grayish brown, of a dull 

 aspect, not transparent, with many portions of wood and bark inter- 

 mixed with it. But the finest sorts in the European market are got 

 from Siam ; the produce, perhaps, according to the conjecture of Dr. 

 Royle, of Stijrax Pinlaysoniauum. " It occurs in tears, in irregular 

 lumps, and hi cubical blocks ; but unlike the Sumatra sort, it never 

 conies over enveloped in calico." Pereira. 



Benzoin is of the specific gravity of 1'063, is friable and easily 

 powdered, during which process it causes sneezing, has an agreeable 

 balsamic odour, and tastes at first sweetish, afterwards balsamic and 

 stimulating. It melts at a moderate degree of heat, and evolves a 

 white smoke and pleasant odour. The fumes which arise consist of 

 benzoic acid, which may be easily condensed in a white flocculent mass, 

 called flowers of benzoin. The odour is attributed by Dr. Thomson to 

 the presence of a volatile oil, which accompanies the acid. 



Benzoin is entirely soluble in alcohol and ether, but insoluble in 

 fixed or volatile oils. Its alcoholic solution added to water becomes of 

 a milky appearance. 



Stolze analysed the white and brown kinds, and found them to 

 consist of 



White Benzoin, Brown Benzoin, 



100 parts. 100 part). 



Yellow resin, soluble in ether . 79-63 8-80 



Brown resin, insoluble in ether . . 0-25 69-73 



Benzoic acid 19-80 19-70 



Extractive 0-00 O'lS 



Impurities 0-00 1'IS 



Moisture and loss . . . . 0*12 0-17 



A trace of volatile oil. 



Bucholz, John, and Kopp have analysed benzoin, but none obtained 

 more than 14 per cent, of benzoic acid; the two former only 12. 

 Wackenroder got only 9 per cent, of benzoic acid from Siam benzoin. 

 ' Pharmac. Central-Blatt.,' fur. 1843, p. 336. 



In its action on the system, benzoin resembles the other balsamic 

 resins ; being stimulant and exciting, aa well as improving the quality 

 of the secretions of the mucous membrane of the lungs. It was 

 formerly employed as an expectorant in chronic catarrh and in asthma ; 

 and it may occasionally be serviceable when, from deficiency of nervous 

 energy, expectoration is difficult, and an accumulation of mucus takes 

 place in the lungs. It cannot fail, however, to prove hurtful if such 

 accumulation arises from difficult circulation through the lungs, con- 

 nected with organic disease of the heart, which is frequently the 

 source of the spasmodic symptoms called asthmatic. It has also been 

 recommended in cases of imperfect development of cutaneous eruptions, 

 but it cannot be relied on in such cam. 



In the present day it is chiefly employed to yield benzoic acid, and as an 

 ingredient in pastilles, or to burn in censers in Roman Catholic churches. 

 It enters into the composition of the Tinctvra benarini cumpotita, the 

 use of which is mostly confined to old ulcers ; its application to recent 

 wounds is very improper. [BALSAMS.] A solution of benzoin in 

 alcohol, added to twenty parts of rose-water, forms the cosmetic called 

 Virgin's milk. 



BKNZOINAM, CjjNjH^O,. When a mixture of ammonia, alcohol, 

 and benzoin is left in a closed vessel for some months, several new 

 products are formed, amongst which is Benzainam. It occurs in the 

 form of small white needle-shaped crystals. It dissolves hi acids, and 

 is precipitated by alkalies. 



BENZOINAMIDE = HYDROBENZOINAMIDE (C 8 .H 30 N,), is 

 formed by exposing a mixture of benzoine and ammonia. It is a white, 

 tasteless powder, and volatilises without decomposition. 



BENZOLACTIC ACID. ("LACTIC ACID.] 



BENZOLE (C^H,), or hydride of phenyl (C,,H 5 H), in the impure 

 state in which it occurs in commerce also called benzine, benzaline, 

 and benzine cuttai, is a product of very frequent occurrence in the 

 destructive distillation of many substances rich in carbon, such aa the 

 fata, fatty acids, coals, alcohol, &c. Benzole is best prepared when 

 wanted in small quantities by heating benzoic acid with three times its 

 weight of slaked lime. The distillate is separated from tho water, 

 agitated with potash, and rectified. Benzole also occurs in the liquid 

 which accumulates in the condensers of coal-gas works. The more 

 volatile portion of this liquid is re-diatilled, the still being so arranged 

 that the worm is heated to 212 Fahr., and the portions which con- 

 dense at this temperature run back into the retort. On the second 

 rectification, the worm U only heated to 176 Fahr., and the distillation 

 is discontinued as soon as the contents of the retort reach 194. 

 The distillate so obtained is treated with dilute nitric and then with 



strong sulphuric acid, and submitted to a cold of 11 Fahr., at which 

 temperature the benzole solidifies, and may be freed from the non- 

 solidifying hydrocarbons by pressure. 



Benzole is a colourless limpid liquid of agreeable odour. Specific 

 gravity 0'9 at 32 Fahr., and 0'85 at 59 Fahr. Boiling point, 176 to 

 178 Fahr. Vapour density, 2752. Point of congelation, 32 ; point 

 of liquefaction, 43 Fahr. Benzole is insoluble in water, but soluble 

 in alcohol, ether, and acetone. It is a solvent for sulphur, phosphorus, 

 and iodine to a small extent. It readily dissolves the fata, camphor^ 

 wax, caoutchouc, and gutta percha ; the resins are dissolved by it with 

 difficulty. Of the alkaloids, the four quinine, morphine, strychnine, 

 and cinchonine are dissolved in the above order in respect to quan- 

 tity ; the last, cinchonine, being insoluble. Benzole, by itself, burns 

 with a white but smoky flame, owing to the large quantity of carbon 

 which it contains. Since however alcohol and benzole have nearly the 

 same boiling point, a mixture of the two may be made to give a bright 

 yet smokeless flame (1 vol. of benzole with 2 vols. of spirits of wine at 

 85 per cent, is a good proportion for this purpose). The illuminating 

 power of ordinary coal-gas may be also much increased by passing it, 

 previous to ignition, through benzole. 



One, two, or three atoms of hydrogen in benzole may be replaced by 

 bromine, the substitution products being mono-, bi-, and tri-brombenzole 



TT 



respectively. Monobromlenzole, C 12 g r *H, or the hydride of monolrom- 



phenyl, is obtained by conducting the vapour of bromine into a flask in 

 which some benzole is heated to ebullition. As soon as two equiva- 

 lents of bromine have been added, the contents of the flask are washed 

 with aqueous potash, dried, and distilled. Monobrombenzole is a 

 colourless liquid, which boils at 302 Fahr., and whose vapuur density is 

 5'63. Fuming nitric acid converts it into mono-bromnitrobenzole, 



H 3 

 C 12 Br H, a solid volatile body, which melts at 194. On leaving 



NO, 

 monobrombenzole in contact with bromine, hydrobromic acid continues 



to be evolved, and bibromfoenzuU, C 12T , 3 H, separates out in large crys- 

 tals, which are purified by solution in ether and spontaneous evapo- 

 ration. Bibrombenzole melts at 192, and boils at 426 D Fahr. 



If the bibrombenzole be boiled with alcoholic caustic potash, and the 

 product precipitated with water and dissolved in ether, a solution is 



TT 



obtained from which (ribrombenzole, C 12T , - H, separates out as fusible, 



"3 



sublimable needles, soluble in alcohol and ether. The above compound 

 may also be directly obtained, in combination with hydrobromic acid, 

 by submitting benzole to the action of bromine in the direct sun-light. 



Its formula is C 12 j> 2 H + 3HBr. It is very insoluble in alcohol, ether, 



and water, not volatile without decomposition. Caustic lime converts 

 it into tribrombenzole. 



TT 



A similar chlorine compound, C 12( ~,j 2 H + 3HC1, the terhydrochlorate 



nf trichtwbenzole, is formed when chlorine is passed into benzole in the 

 direct sun-light. This body, like the preceding, is a solid crystalline 

 one, which may be purified by resolution in alcohol. It melts at 

 275 Fahr., and boils at 576. On digestion with alcoholic caustic pot- 

 ash it is converted into trichlorbenzole, C laf ,^H, which is a colourless 



oil, of the specific gravity 1-457 at 44'6. It boils at 410 Fahr., and its 

 vapour density is 6'37. The same substance is also obtained by the 

 action of caustic lime or baryta upon chlorbenzole. 



One or two atoms of hydrogen of benzole may also be replaced by 



the group N0 4 , the resulting bodies being the nitrobemole, C 12 ^-k H, 



TT 



and liinitrobenzole, or dinitrokenzole, C l2 /jrQ \ H, respectively. Nitro- 



benzole is prepared by gradually adding benzole to warm fuming nitric 

 acid. On allowing the mixture to cool, the nitro-benzole separates out 

 as an oil, which, after washing with water, is dried and rectified. 

 Specific gravity, 1'209 at 59. Boiling point, 427. Vapour den- 

 sity, 4'40. It solidifies at 37'4. It is insoluble in water, soluble in 

 nitric and sulphuric acids, as also in alcohol and ether. On account of 

 its odour closely resembling that of oil of bitter almonds, and on 

 account of its greater cheapness, it is used in perfumery as a substitute 

 for the latter substance. 



Dinitrobenzole is best prepared by dropping benzole into a hot mix- 

 ture of equal parts of fuming nitric acid and oil of vitriol, allowing the 

 mixture to boil for a few minutes, and then washing the crystals, which 

 separate out on cooling in water, and recrystallising from alcohol. 

 Dinitrobenzole crystallises in long needles, which melt at 212, and are 

 insoluble in water, but easily soluble in alcohol, 



As benzole properly belongs to the phenyl group, the numerous 

 derivations to which it and its nitro-substitution products give rise will 

 be described under the head PHENYL. 



BENZOLE LIGHT. [LIGHTS, ARTIFICIAL.] 



BENZOLINE. [AMARINE.] 



BENZOLONE, (C.,11.0)? When ffi/drobenzamide (C,.,H ]8 N 2 ) is 

 heated with potash till it becomes blackish-brown, this compound is 

 formed. The mass, when washed with water, yields benzolone in the 



