Note-book of materia medica, pharmacology, and therapeutics / by R.E. Scoresby-Jackson.

  • Robert Scoresby Jackson
Date:
1866
Catalogue details

Licence: Public Domain Mark

Credit: Note-book of materia medica, pharmacology, and therapeutics / by R.E. Scoresby-Jackson. Source: Wellcome Collection.

    36/652 (page 20)
    tion or b}'’ incisions into the barks of trees. The varieties are not readily distinguished; they have been classed into soluble gums, and those which swell up in cold water ; of the former of which Arabine is the type, and of the latter Tragacanthine or Bassorine. Pectose, Pectin, Pectic Acid, Vegetable Jelly.—Pectose exists in the succulent roots and acidulous fruits of many plants, and is con- verted by the organic acids, and by heat and light, into a soluble gelatinous substance called pectin, pai'apectin, pectic acid, &c. Pectin is formed during the ripenmg of the fruits, and gives the gelatinous character to the juices of currants, raspberries, &c., and also to the juices of some medicinal roots, such as gentian, dandelion, &c. Cellulose, Lignin, Woody Fibre.—Cellulose or cellular matter is an organised substance, without colour, taste, or smell, translucent when freed from foreign matter, and medicinally inert, occupying the cell walls of plants, and forming the pure base of woody fibre. It is nearly insoluble, and by the aid of sulphuric acid is convertible into dextrine. It is as much as possible excluded from nearly all pharmaceutical preparations used mternally, but lignin is used ex- ternally in the form of cotton and lint, and enters into the com- pounds pyroxylin (gun-cotton) and collodion. Proteic or Albuminoid Siibstances.—Besides the ternary proxi- mate principles already enumerated, there are in all plants and animals certain neutral nitrogenous compomids, consisting of C, H, 0, and N, for the most part in combination with sidphur and phos- phorus. hlulder was the first to point out the general resemblance between these bodies, as existing in the vegetable kmgdom, where they are represented by gluten, albumen, casein, or legumin, and in the animal kingdom, where they are met Avith as fibrin, albumen, casein, and gelatin, their constitution being almost identical in both kingdoms. With the exception of gelatin, these substances are said to be derivatives from a common principle, Avhich, according to Mulder, consists of CggHogN^Ojo, but according to Liebig, and others, of 04sH3gNgO]4 ; and it has been supposed that this prin- ciple, in combination Avith various proportions of sulphur and phos - phorus, yields the above-mentioned, and hence so-called proteic compounds. These principles, accordmg to the modern chemical theory, form Avhat are called the fiesh-forming articles of diet, as distinguished from the non-nitrogenous ternary compounds, starch, sugar, and gum, Avhich are said to be merely heat-producing sub- stances. Although their composition is Avell understood, yet no definite chemical formulse have been constructed to represent their