57 



The C. thus obtained, contains resin and mineral substances ; the 

 former may be removed by means of ether ; the latter by dis- 

 solving repeatedly in water, precipitating with tannic acid and 

 treating as above. — White powder, intermixed with small crystals 

 of a peculiar, lasting, sweet-bitter taste ; is softened by heat and 

 afterwards destroyed ; dissolves readily in water and in alcohol, not 

 in ether, is soluble unaltered in liquor of ammonia, assumes a 

 beautiful violet colour with concentrated sulphuric acid ; is resolved 

 by diluted acids into sugar and a resin (Convallamaretin). 



Convallarill=C34 H31 On. In Convallaria majalis. Boil 

 •with water the whole herb, collected with the i-oots while 

 blossoming or shortly after the time of inflorescence, employ the 

 ■decoction for the j^i-eparation of Convallamarin (see this), exhavxst 

 the remnant with alcohol of 0"84, precipitate the tinctures with 

 subacetate of lead, remove the lead from the filtrate by suljjhuret 

 of hydrogen, distil off the alcohol and let crystallise. The 

 ■crystals, mixed with resin and chlorophyll, must be pressed and 

 washed with ether. — Forms rectangular prisms, has a rancid taste 

 when dissolved in water or alcohol, fuses at 100° and is after- 

 wards destroyed, dissolves very little in water, readily in alcohol, 

 not in ether, divides under the action of diluted acids into sugar 

 and a resin (Convallaretin). 



Convolvillill=:C62 H50 O32. The main ingredient of the resin 

 of Ipomaca Purga. Boil the root first with water, afterwards 

 with alcohol, add water to the tincture until it shows traces of 

 turbidity, boil with animal charcoal, filter and evaporate. The 

 yellowish, brittle resin is reduced to powder, exhausted with 

 •ether, dissolved in absolute alcohol and precipitated by ether. — 

 Colourless substance, at 100° brittle and reducible to a white 

 powder, without taste or smell, fuses at 150° without loss and de- 

 ■composes afterwards, has a slightly acid i-eaction when dissolved 

 in alcohol, dissolves very little in water, in any qixantity of 

 alcohol, not in ether or in oils, both fixed and volatile ones, 

 xeadily in acetic acid, in concentrated sulphuric acid with carmine- 

 red colour, in alkalies and and alkaline earths under formation of 

 an acid and not reprecipitable by acids, breaks up with diluted 

 acids into sugar and an oily product. 



Copaiva ßalsaill. Exudation of the stems of various kinds of 

 Copaifera. Is pale-yellow, of honey consistence, of 0*94 to 0*95 

 density, has a peculiar, unjoleasant balsamic smell and an aromatic, 

 bitter taste, of acid reaction, dissolves copiously in alcohol of 90%, 

 mixes with ether and oils in every proportion, dissolves mostly 

 clear in liquor of ammonia and in potash-ley, hardens with 1-1 6th 

 caustic lime or magnesia to a solid paste. Consists of volatile oil 

 (up to 80°/^), of two resins, the one of which is prevailing and 

 hard (copaivic acid), the other soft, and of metacopaivic acid. 



