Cold water has very little effect on benzoin, but boiling water takes up a portion of benzoic acid. 
Alcohol dissolves it when assisted by a gentle heat, and forms a deep yellow solution inclining to 
reddish-brown. When this solution is diluted with water, the benzoin precipitates in the form of a white 
powder. It is precipitated also by muriatic and acetic acids, but not by the alkalies. A few drops of sul- 
phuric acid likewise precipitate the benzoin: but an additional quantity will re-dissolve it, and form a liquid 
of the colour of port wine. When equal quantities of the alcoholic solution of benzoin and sulphuric acid 
are mixed, a dark-pink precipitate falls. The liquid assumes a pink colour, which becomes lilac when 
diluted with water. Nitric acid occasions a strong effervescence, and forms a dark-red fluid with the 
alcoholic solution, but throws down no precipitate. 
Ether dissolves benzoin with facility, and the solution, with re-agents, exhibits the same phenomena 
as the alcoholic. 
Nitric acid acts with violence on benzoin, and converts it into an orange-coloured mass. When 
assisted by heat the acid dissolves the benzoin ; and as the solution cools, crystals of benzoic acid gradually 
separate. Mr. Hatchett ascertained that by this process a quantity of artificial tannin is formed. 
Medical Properties and Uses. — This balsam was formerly considered to be expectorant and was 
esteemed for its virtues in asthma and other pulmonary affections; it is now, however, little used in 
practice, and is chiefly valued as yielding the benzoic acid which is somewhat stimulating, and imparts a 
pleasant flavour to other medicines. 
Benzoin is also used in the preparation of what is called court plaster, which it sometimes renders too 
irritating. The mode of making it is as follows : — Five ounces of isinglass are dissolved in a pint of water. 
A quantity of thin black sarcenet being stretched on a frame, this solution is applied warm with a brush 
equally over the surface; and, when dry, the process is repeated a second or third time. It is finally 
brushed over with a weak solution of benzoin in spirits of wine, which communicates to it a pleasant 
aromatic smell. 
Benzoin also enters into the composition of the following preparations : — 
1. Fumigating Pastilles. 
Take of Benzoin, 1 drachm. 
Cascarilla bark, \ drachm 
Myrrh, 1 scruple. 
Oil of nutmegs I of each 10 d 
Oil of cloves J 7 r 
Nitrate of potass, \ drachm. 
Charcoal, 6 drachms. 
Mucilage of gum tragacanth, as much as may be required, to cause the mass to adhere ; after which it is to 
be divided and cut into the usual form. 
The following is the French method of preparing pastilles : 
“Prenez, Benjoin .... 16 parts. 
Baume du Perou sec 16 
Qu’on a fait prealablement dans l’eau 
pour enlever tout l’acide volatil. 
Santal citrin .... 4 
Ladanum .... 1 
Charbon de tilleul ... 96 
Nitrate de potasse ... 2 
“ Reduisez toutes ces substances en poudre tres fine, melez-les exactement, et faites-en, avec du muci- 
lage de gomme adraganthe, une masse £paisse, dont vous formerez des cdnes echancr^s en trepied a la base, 
que vous ferez secher dans un four faiblement chaufK.” 
2. Virgin’s Milk. — A spirituous solution of benzoin mixed with about 20 parts of rose water, forms a well- 
known cosmetic. Goulard water is also sometimes sold under this title. 
3. Friar’s Balsam, Wade’s Drops, Jesuit’s Drops. — These preparations are nothing more than the com- 
pound ticture of benjamin. 
4. Pectoral Balsam of Honey. — This is merely a simple tincture of benzoin, or of tolu, and like the 
following, is highly stimulant and improper for those diseases for which it is usually commended. 
5. Essence of Coltsfoot, consists of equal parts of balsam of tolu, and the compound tincture of benzoin, 
to which is added double the quantity of rectified spirits of wine. It is recommended for coughs and 
consumptions ! ! 
Riga Balsam. — Take of alcohol or rectified spirit, eight ounces; compound tincture of benzoin, two 
drachms; tincture of saffron, one drachm : mix. A popular nostrum for sprains and bruises: recommended 
also as a vulnerary ! 
Off. Prep* — Acidum Benzoicum. L. E. D. 
Tinct. Benzoini composita. L. E. D. 
