224 



for the greatest part from tlie deposit by alcoliol containing 

 liydrochloric acid. — The Mucilage is, after drying, yellowish, not 

 so translucid as gum, more tough than brittle; swells up consi- 

 derably in water, and dissolves to turbid, ropy, neutral liquids, 

 which in many cases are thrown down by acids and by many salts 

 that do not affect the solution of gum, as for instance by alum, 

 subchloride of tin, acetate of lead ; but on the other hand they are 

 not turbidified by silicate of potash, nor thickened by borax. 

 Nitric acid produces oxalic and partly mucic acid. By the agency 

 of diluted sulphuric acid, at first gum, then sugar is formed. The 

 different behaviour of different Mucilages is prol^ably caused by 

 the greater or less amount of salts, though this assumjition is con- 

 tradicted by Frank (Chem. Jahresb. für 1865, 598). 



The presence of Mucilage can be best detected by directly treat- 

 ing with cold water. For this purpose the roots, barks, leaves and 

 stalks have to be reduced to a proper state by bruising, cutting, 

 etc.; seeds are left whole, as they contain the mucus in the epi- 

 dermis, and witli them, bruising would be either superfluous or 

 detrimental to the purity of the product, because the water would 

 dissolve, or keep suspended, substances that could not be easily 

 removed, as albuminous substances, oils, etc. — The quantitative 

 estimation of Mucilage is also effected by direct treatment with 

 cold water ; after subsiding and straining, the liquid must be boiled 

 a few moments. Now, strain off the flocky deposit of albumen, 

 evaporate to a small bulk, precipitate with alcohol, wash the 

 deposit with alcohol and dry at 110°. As salts of lime (generally 

 the phosphate) are always present, their weight has to be deter- 

 mined by incinerating a weighed quantity of the dried Mucilage 

 and weighing the ash. The weight of the latter has to be deducted 

 from that of the Mucilage. 



Verailtill=:Ci4 H^ O5. In the root of Rubia tinctorum. 

 Liberate the Verantin oxyd of iron (see Rubiacin) from the 

 metallic base by boiling with hydrochloric acid, wash and dissolve 

 in boiling alcohol, when the Verantin will separate on cooling as 

 a brown powder. — Reddish-brown, amorphoiis powder similar in 

 appearance to snuff or ground roasted coffee; fuses scarcely in 

 boiling water and dissolves sparingly in it, dissolves readily in 

 boiling alcohol and separates on cooling in a pulverident form, 

 the solution retaining an acid reaction ; dissolves in alkalies with 

 a brown colour; is decomposed by heat. 



Vera trie 4cid:=:Ci8 H9 O7 + HO. In the seeds of Schoeno- 

 caulon officinale. Exhaiist the pulverised seeds with alcohol 

 acidulated with sulphuric acid, add to the tincture hydrate of 

 })otash, filter, distil the alcohol, collect the verati'in thus deposited 

 and satui-ate the mother-ley with excess of siilphuric acid, when 

 the V. acid will crystallise slowly before or after evaporation. 



