October i, 1884.] 



THL TROPICAL AGRICULTURIST, 



285 



by separation, ami finally dried by means of anhydrous 

 calcic chloride. 



This process requires considerable care and the avoid- 

 ance of high temperature. The loss in purification varies 

 from tf per cent to lo per cent; and, unless the oil is 

 well dried by calcic chloride, oxidation is quickly set up, 

 and large masses of crystals of benzoic acid are formed. 

 I have observed, in course of business, a bottle to go 

 entirely solid, except a thin stratum of a very limpid 

 fluid entirely destitute of the odour of almonds. 



Distillation with red oxide of mercury, after a few days' 

 occasional agitation, is a very handy method for small 

 quantities, and the following data may be useful: — 



Take a small retort (tubulated and stoppered), pad it 

 round with asbestos, and place in a cradle of iron gauze. 

 Half fill the apparatus with the oil, which has been 

 allowed to remain in contact with red oxide of mercury 

 in sufficient quantity to cover a possible 12 percentage of 

 hydrocyanic acid, insert a thermometer through the stopper, 

 and regulate the heat at no time to exceed 280° Fahr. 

 The cyanide of mercury may be re-converted to the 

 metallic state. 



The purified oil should be of sp. gr. 11)10 to 1051. 

 Analysis of Trade (Specimens. 

 Loss in Volume 



Nos. Sp.gr 

 1... 



3... 



4... 

 5... 

 6... 



when treated 

 with water 

 Per Cent. 

 ... 1115 

 ... d'725 ... 

 ... U'75 

 ... 125 ... 

 ... 1-25 ... 

 ... 100 ... 



i-o; 



Solidified. 

 Slightly at 32° F. 



Boiled. 

 291 ° F. 

 283 ° F. 

 280 : K. 



294 °F. 



295 = F. 

 285 ° F. 

 283 ° ¥. 



not been 



L-068 



1-050 

 l-i «1 

 1-078 

 1080 

 1-065 

 7 .. 1063 

 Sample No. 7 was slightly turbid, and had 

 sufficiently dried. 



The adulterations generally sought for, and in some 

 cases found, are the artificial oil nitro-benzole, or essence 

 of myrbaue and alcohol. The pure oil gives a blood-red 

 colour with acid sulphuric and nitric acid 1 1-120/; no 

 action at first, but subsequent deposition of ciystals of 

 acid benzoic. 



Table I" Detect Impurities. 

 Loss in Volume 

 when treated 

 with water 

 Per Cent. Solidified. 



Sp. gr 



Oleum, amygdal. 

 esseut., crude 1-068 



Oleum, amygdal. 

 essent., sine 

 acid, prussic ...1-050 



Oleum, amygdal. 

 essent., crude, 

 with 5 per cent, 

 nitro-benzole... 1'073 



Crude oil. with 10 

 per cent nitro- 

 benzole 1-081 



N i t i n-benzole, 

 finest 1-209 



Crude oil, with 10 

 $*■ cent alcohol 1 "050 



1-05. ..Slightly at32°F. 



Boiled. 

 .291 °F. 



.294 ° F. 



Mm. ..Slightly at 35 ° F...308 ° F. 



000. 



nil. 



.Slightly ai 37 °F. 

 .Solid at 37°F. ., 



10-i 



.338 ° F. 

 .115 -F. 

 .275 °F. 



Oleum amygdalae essens c. 5 per cent alcohol was treated 

 with fuming nitric acid: a sharp effervescence and yellow 

 colour developed. The dose of the crude oil J to 1 drop, 

 but usually sold in form of an essence of 1 to 9 of spirit. 



Olecm CajapuTjB, distilled from the leaves of Metateuca 

 minor. The trees yielding tins.' leaves grow ex ensivelv 

 in the Matayan Archipelago. The soil is imported from 

 Singapore and Batavia. Mttateuca minor also grows in 

 Australia, but the leaves are not applied to commerce. 



For samples were tested, and all gave evidence of copper 

 contamination. 



Solu- Loss in vol. Postassic 

 tion in when treated ferro- 

 - Boiled. alcohol, withwater. cyanide. 



£ First 3 Parts. 



Submitted to Re-distillation. 



Last Part. 



1 Colourless.. .Slightly tinted green. ..Sp.gr.of firstreserve 916 



, " - " » „ 010 



,. " - " ' ,. 918 



" - .<■'„■ , ", - » » -9L5 



* slight odour of tar. 



From the above it will be seen that the samples were 

 very uniform. I do not attribute the characteristics of 

 No. 1 to any sophistication, but probably, when the original 

 bottle was opened, some of the black sealing-wax became 

 mixed with the oil. Original bottles of cajuput oil are 

 corked with a piece of reed or soft bamboo, and waxed 

 at the end. 



1 have a sample of oil which has been thrice re-distilled 

 from phosphoric anhydride. The camphoraceous odour has 

 been removed and that of hyacinths substituted. This is 

 due to a principle termed cajaputene. The oU is used 

 externally as a stimulant, and is sometimes administered 

 internally iu certain cases of cholera. 



Copper was proved to be prsseut, first by treating the 

 oil with a little weak solution of ammonia; upon stand- 

 ing, the oil was left colourlest,, and the aqueous solution 

 blue. 



Second test: After evaporating some of the oil to dry- 

 ness, the residue was dissolved in nitric acid, and tested 

 for copper with ferrocyanide of potassium. 



OLEt'M Caryophtixi, distilled from the flower-buds of 

 ( 'aryophf llus aromaticus. 



The cloves on the market vary as much in their source 

 as in price— Amboyna, Penang, Mauritius, Zanzibar, Java. 

 Reunion, &e. Most of the oil of English commerce is 

 obtained from Zanzibar cloves and stalks. The islands to 

 the east of Zanzibar furnish some very good samples of 

 cloves, and the island of Seychelles has also exported some 

 oil of very good quality. The oil obtained from Germany 

 is also principally from Zanzibar cloves. The yield varies 

 from 12 to 22 per cent. 



Commercial Samples. 

 No. 1... English ...Sp.gr. 1-050. ..Pale straw colour 

 „ 2... „ ... „ 1-057. ..Straw 



„ 3. ..German ... „ 1-048... „ „ 



„ 4... „ ... „ 1-052. ..Tale straw „ 



„ 5... „ ... „ 1-050.. .Reddish-brown colour 



„ 0... From stem.. „ 1040.. .Brownish 



The oil distilled from clove stems may be distinguished 

 from that obtained from the flower-buds by giving a deep 

 violet colour if shaken up with metallic iron. 



The true oil is very soluble in alcohol, and castor oil, 

 if used to adulterate it, will be first thrown out upon 

 diluting the alcoholic solution with water. 



If caustic potash be added to the alcoholic solution the 

 oil is converted into a crystalline solid, destitute of the 

 true odour of cloves. 



Some months ago a sample of clove-water was shown 

 me, which after standing gave a precipitate. It was in- 

 vestigated by a number of this Association, Mr. F. H. Alcock, 

 and found to be eugenate of lead. The presence of lead 

 is accounted for by the fact that the worm of the con- 

 denser was not of block tin, or was a mixture of tin and 

 lead. It would be of interest to know to what extent 

 eugenic ami is capable of acting on the various metals. 



The colour of oil of cloves deepens considerably on keep, 

 ing, and also becomes denser on long exposure to the air. 

 due to evaporation of the 'lighter v sp. gr. 920) of the 

 two oils, the sp. gr. of the heavier oil being as high as 



1-1 1,811. 



i H i i i i <i ah: i E.-sknt. — A colourless or slightly greenish 

 oil, yielded by copaiba, in quantity varying from 36 per- 

 cent to Oil per cent. 



The Para balsam yields by tar the largest proportion 

 of oil and has the best aroma. It is necessary to take 

 mt, i reckoning the age of the balsam. 



The sp. gr. varies from 678 to '900. 



The largest proportion of the oil found in commerce 



is practically a bye-product fr those wholesale bouses 



who make a specialty of liquor copaiba solid,],., with its 

 long string of compounds, existing iu some cases more on 

 tin lain! than in the preparations. 



The slight green noticed in some samples is produced 

 by the use of copper vessels iu manufacture. 



