TEREBINTH TRIBE.

1181

so as to

s *° Mr. E. Solly, the gum, when purified by simple solution of water,e Parate the impurities, consists of tannin 73-26, difficultly soluble extractive 5-05,Wm (wj^ 1 y a m c all j 0 ther soluble substances) 21-67. It is used by the nativesJ^°rth-Western India , for precipitating their indigo, and in tanning.

Indigo (pigmentum indicumj ivdiuov, Dioscorides; indicum, Pliny ) is a blue pig-obtainable from various plants by fermentation. The ancients also applied

te rm t Voikov, or indicum, to some other substances (Beckmann, Hist, of Inv. and*Jis cov • — - •• • , r ' ’■ -

iv. 118 ).Pig. 220.

The indigo of commerce is procured from the genus Indigo/era.In India , I. tincto'ria is commonly cultivated for this pur-pose. During the fermentation, the indigo deposits as afeculent matter. Lime-water promotes its separation.Blue indigo does not exist in the plants previous to fermen-tation : it is, therefore, a product, not an educt, of them.Commercial indigo is principally brought from the EastIndies, but a considerable quantity is imported fromGuatemala , and other places. It usually occurs in cubicalcakes of an intense blue colour. Rubbed with a smoothhard body (as the nail), it assumes a coppery or bronze hue.This distinguishes it from Prussian blue , the coppery hue ofwhich is removed by friction with the nail. It is insolublein water, cold alcohol, ether, diluted sulphuric or hydro-chloric acids, weak alkaline solutions, and cold oils (bothfixed and volatile). When heated to about 550° F. ita reddish violet vapour (vapour of indigotin) which condenses in minutec attl ■ Deoxidizing agents (as protosulphate of iron, sesquisulphuret of arseni-OXy’ *-^ e process of fermentation, &c.) destroy its blue colour by abstractingto th ' f r,im the indigotin, and converting it into indigogen; which, by exposuredest,. 6 a ' r > attracts oxygen, and

^ndigofera tinctoria.

ue str -■■> auracis oxygen, and becomes blue. Chlorine and the hypochloritesliqyjVP Re blue colour of indigo. Rubbed with oil of vitriol it yields a deep blueiriJlj > c °mmonly termed sulphate of indigo, Saxon blue, or liquid blue. Commercialcons ' s t s °f indigo blue (indigotin), indigo-brown, indigo-red, and a glutinouslate atlCe ' Indigotin consists, according to Dumas, of C 1S H5 N 1 O 2 . Indigo has, ofbeen employed as a medicine. Its physiological effects, according to Dr.p. Inaug. de Indico, 1834, Berol., and Brit, and For. Med. Rev. vol. ii.

are as follows:—Shortly after takina- it. the natie

s tri,

ar e " ..'“l 1 at the fauces, and the impression of a metallic taste on the tongue. Thesesv>«. U ° We d by nausea, and frequently by actual vomiting. The intensity of these'aries in different cases. In some the vomiting is so violent as to precludef use of the remedy. The matter vomited presents no peculiarity except incolour. When the vomiting has subsided, diarrhoea usually occurs : the stoolsdia,.^ ° re frequent, liquid, and of a blue or blackish colour. The vomiting andsyinpt 061 are frequently accompanied by cardialgia and colic. Occasionally these° m . s increase, and the use of the remedy is in consequence obliged to be omitted.l)Ut D and giddiness sometimes succeed. The urine has a brown, dark, violet colour;for a .. r - Roth never found the respiratory matter tinged with it. After the use of indigos.ry c ,i e * "’eeks, twitching of the muscles sometimes were observed, as after the use ofCoi lv . ! a - It has been employed principally in spasmodic affections—viz. epilepsy,Stab] sl ons °I children, chorea, and hysteria. In epilepsy it has been tried by Vont>i e ,-b ’ i 'cohossek, Grossheim, Ideler, Wolf, Leinevveber, Doepp (Roth, op. cit.;.°m. * i’ Ne ^ st Entd - in d Mat Med - Bd - I. s - 222, 1837), and Noble (LandMed.l°hg st ° \* vii - p. 1038), with good effect. Some of the successful cases were of very°r the and ' n g- Roth says, that at the commencement of the treatment, the frequency*Hor e j J l >aro . x ysms was invariably increased. Idiopathic epilepsy is said to have beenWg f . a fcl 'chted by it th an the symptomatic epilepsy. The dose of indigo should be asS'kflu *• stomac h can bear. At the beginning it may be a few grains; afterwardskotn e f 1 ,*1 should be increased to drachms, or even an ounce or more in the day.

V. 1 , 6 patients above referred to, took from Jss. to Jj. daily, for three or more?1e p a ‘ B h e best mode of exhibiting it is in the form of an electuary, composed ofapt t 0 °* lnd 'ff° and two parts of syrup, with a small portion of water. The powder(as t]j e cause spasm of the fauces. Aromatics, mild tonics, astringents, and opiatesst atice s COm P°nnd powder of ipecacuanha), may be conjoined, according to circum-

are as follows:—Shortly after taking it, the patient experiences a sense of cou-

e '>nhe