The substance which most powerfully excites the sugar fermentation was first shown by Payen and Persoz to be a peculiar principle to which they have given the name of ‘DIASTASE,’ This is always present in good malt, and possesses the singular property of converting STARCH successively into gum (dextrin) and sugar, at a temperature ranging between 149° and 168° Fahr. During the action of this substance on starch it is itself decomposed; and when the sugar fermentation ceases it is found to have entirely disappeared. It is the presence of diastase in malt which alone converts the starch of the grain into sugar during the operation of mashing with hot water; and hence the absolute necessity of employing water at the proper temperature, as on this depends the strength and sweetness of the wort, and consequently its fitness for undergoing the vinous fermentation, and for making beer. Vegetable albumen and gluten also possess the property of exciting the saccharine fermentation, but in a considerably inferior degree to diastase.
The sugar formed during the germination of seeds containing starch results from the action of diastase, and disappears as soon as the woody fibre (lignin), which has a similar constitution, is developed, forming the skeleton of the young plant. (Liebig.) See Brewing, Diastase, Dextrin, &c.
SACCHAROM′ETER. An instrument similar in principle to the common spirit hydrometer, but so weighted and graduated as to adapt it for the indication of the richness of malt-worts in sugar, or saccharine, expressed in pounds per barrel, or the excess of gravity over that of water, the last being taken at 1000. See Brewing, Syrup, Wort, &c.
SACH′ET. Syn. Sacculus, L. Sachets (SACCULI) are little bags containing dry substances, used for the external medication of parts, or for communicating agreeable perfumes to wearing apparel, drawers, furniture, &c. Those belonging to perfumery are commonly filled with mixtures of fragrant vegetable substances, reduced to coarse powder, and differ from those employed for pot pourri chiefly in being used in the dry state. Sacculi are now seldom employed in this country in legitimate medicine. See Powders (Scented), &c.
Sachet, Ammoniacal. Syn. Sacculus ammoniacalis. Prep. Equal parts of sal ammoniac and quicklime are mixed, and sprinkled
between cotton wadding, which is to be quilted in muslin.
Sachet, Anodyne. (Quincy.) Syn. Sacculus anodynus. Prep. Chamomiles, 1 oz.; bay berries, 1 oz.; lavender flower, 1⁄2 oz.; henbane seed, 1 dr.; opium, 1 dr. To be dipped in hot spirits.
Sachet, Anti-phthisic. Syn. Sacculus anti-phthisicus, L. Prep. Dissolve of aloes, 1 oz., in strong decoction of fresh rue, 1⁄2 pint; next fold a piece of soft muslin in eight folds large enough to cover the chest and part of the stomach; steep this in the decoction, and dry it in the shade; lastly, place in a small bag, one side of which is formed of scarlet silk or wool, and the other, intended to be worn next the skin, of the finest net or gauze. A celebrated domestic remedy for consumption and asthma. It is intended to be constantly worn on the chest.
Sachet, Resolv′ent. Syn. Melting bag; Sacculus resolvens, L. Prep. 1. (Dr Breslau.) Iodide of potassium, 1 part; sal ammoniac, 8 parts; dry, and reduce each separately to fine powder; mix them, and enclose 1⁄2 oz. to 1 oz. of the mixed powder in a small bag of linen or silk. Used as a resolvent to indolent tumours, especially goitres and scrofulous indurations. It should be worn on the part night and day for some time. The part next the skin should be well pricked with a needle, and the powder shaken up and readjusted every 2 or 3 days; and it should be renewed about once a fortnight.
2. (Trousseau & Reveil.) Iodide of potassium, 1 part; burnt sponge, 4 parts; fine sawdust, 5 parts; as before.