Part 138

SENNA, 28% of _soluble matter_.

Medicinal leaves, flowers, barks, roots, extracts, &c., not specified above, must be, when imported, in perfect condition, and of as recent collection and preparation as practicable.

Pharmaceutical and chemical preparations, whether crystallised or otherwise, used in medicine, to be pure and of a proper consistence and strength, as well as of perfect manufacture, conformably with the standard authorities named in the Act; and must, in no instance, contain over 3% of excess of moisture or water of crystallisation.

Essential or volatile oils, and expressed oils used in medicine must be pure and of the standard sp. gr. noticed and declared in the dispensatories named in the above Act.

"Patent" or "Secret Medicines" are by law subject to the same examination as other medicinal preparations, and cannot be permitted to pass the Custom-house for home consumption, but must be rejected and condemned, unless the special examiner is satisfied, after due investigation, that they are fit and safe to be used for medical purposes.

An appeal from the examiner to the collector to be admitted within 10 days.

JAMES GUTHRIE, _Secretary to the Treasury_.

[Footnote 264: Of whatever denomination.]

[Footnote 265: Root in powder.]

[Footnote 266: Only Turkey, East Indian, and Russian, admissible.]

=DRUM'MOND LIGHT.= See LIGHT (Artificial).

=DRUNK'ENNESS.= See ABSTINENCE, INTEMPERANCE, &c.

=DRY'ERS (Painter's).= _Prep._ 1. Litharge (best) ground to a paste with drying-oil. For dark colours.

2. From white copperas and drying oil; as the last.

3. From sugar of lead and drying oil. The last two are for pale colours.

4. From white copperas and sugar of lead, of each 1 lb.; pure white lead, 2 lbs. For 'whites,' and opaque light colours, greys, &c.

Dryers are employed, as the name implies, to increase the drying and hardening properties of oil paints. A little is beat up with them at the time of mixing them with the oil and turpentine for use.

=DRY'ING.= See DESICCATION, &c.

=DRY'ING-OIL.= See OILS.

=DRY-ROT.= A peculiar disease that attacks wood, and renders it brittle and rotten. It is generally caused by dampness and the subsequent development of the spores of fungi, particularly those of _Merulius lacrymans_ and _vastator_ and _Polyporus destructor_. The dry-rot principally attacks 'ill-seasoned' timber, and more particularly that of ships and badly ventilated buildings.

_Prev._ Various means have been proposed to prevent the attacks of dry-rot and to arrest its progress when it has commenced, among which the process called 'KYANIZING' (Kyan's patent) is that most generally known and most extensively adopted. It consists in immersing the timber in a bath of corrosive sublimate. The process termed 'PAYNIZING' (Payne's patent) consists in first filling the pores with a solution of chloride of calcium, under pressure, and next forcing in a solution of sulphate of iron, by which an insoluble sulphate of lime is formed in the body of the wood, which is thus rendered nearly as hard as stone. Wood so prepared is now largely employed in our public works and railways. Sir W. Burnett's process (patented in 1836) consists in impregnating the timber with a solution of chloride of zinc. Mr J. Bethell's process (patented in 1838) consists in thoroughly impregnating the wood with oil of tar containing creasote and a crude solution of acetate of iron, commonly called 'pyrolignite of iron.' The impregnation is effected in a strong cylindrical vessel, connected with a powerful air-pump, so that in the first instance a vacuum being formed, and subsequently a pressure of several atmospheres applied, the liquid may as much as possible be forced into all the pores of the wood. The above processes for 'seasoning' preserve the timber not only from dry-rot, but from the influence of the weather and the attacks of insects and worms.

"The construction of air-drains or passages around wood-work to be preserved is, where the method is applicable, a great aid to the preservation of wood. Dry-rot is both prevented in new buildings and cured in old ones by filling up the spaces between the floor-joists with 'tank-waste' from alkali works. This can also be applied to the ends of beams resting in walls."--_Chemical News._

=DUB'BING.= _Prep._ 1. By boiling the waste cuttings of sheep-skins in crude cod oil. 2. Black resin, 2 lb.; tallow, 1 lb.; crude cod oil or train oil, 1 gall.; boil to a proper consistence. Used by the curriers to dress leather, and by shoemakers and others to soften leather, and to render boots and shoes waterproof.

=DUBOISIA MYOPOROIDES.= (Nat. order, _Solanacæ_.) A small tree growing in Australia, New Caledonia, and New Guinea. The leaves have been used in Brisbane and Sydney as a substitute for atropine, and extract of belladonna; to both of which Mr Tweedy believes them to be superior in prompt and energetic action. Mr Tweedy further states that, in every case in which he has used _duboisia_ to produce dilatation of the pupil of the eye, its action has been beneficial, and he is induced to conclude, more advantageous than that of atropine. According to Dr Ringer, _duboisia_, besides causing dilatation of the pupil, quickens the pulse, parches the tongue, stops the secretions of the skin, and induces headache and drowsiness. He also reports that it is antagonistic in its action to muscarine, and produces tetanus after the lapse of some hours or days.

For an account of the botanical properties of the plant, the reader is referred to a paper by Mr E. M. Holmes in the 'Pharmaceutical Journal' for March 9th, 1878; and to the 'Lancet' of March 2nd, 1878, for some experiments on its physiological effects by Messrs Ringer and Tweedie. The _Duboisia myoporoides_ was introduced into medical practice by Dr Bancroft, of Brisbane.

Since the above has been written, Mr Gerrard has obtained a powerful alkaloid from an extract of the leaves of the Duboisias, very similar in chemical properties to aconite, and possessed of the same physiological qualities as the extract.

=DUCK.= See POULTRY.

=DUCTIL'ITY= is the property of being drawn out in length without breaking. See METALS.

=DULCAMA'RA.= See NIGHTSHADE (Woody).

=DUMB'NESS.= _Syn._ APHONIA, L. As speech is an acquired and imitative faculty, persons who are either born deaf or become so in early infancy are also, necessarily, dumb. The first step in treating dumbness must therefore be directed to the removal of the deafness on which the imperfection rests. The exertions of modern philanthropists have, however, been so far successful in such cases as to enable the deaf-mute to converse with those around him by signs. Those interested in the subject may consult an admirable treatise on 'Deaf-dumbness,' by M. E. Hubert-Valleroux, of which an excellent translation appeared in the 'Medical Circular,' vol. ii, for 1853. See DEAFNESS.

=DUMPLINGS, Norfolk.= Mix half a pound of flour with half a teaspoonful of baking powder and a pinch of salt; make into a little dough with cold water; fall into small balls, put them into boiling water immediately, and boil for twenty minutes.

=DUNGER--MANURE= (Boutin, Paris). A bluish-green fluid, containing about 190 grammes of solid matter per litre. The residue consists of sulphates of copper, iron, magnesia, and soda, sal ammoniac, nitrates of potash and soda, common salt, and none or a mere trace of phosphoric acid. The blue deposit which separates on standing is ultramarine. (Keller, Karmrodt, and Nessler.)

=DUNG'ING.= _Syn._ CLEANSING. One of the principal processes in the arts of calico printing and dyeing, its object being to free the cloth from loose matters, which would interfere with the dyeing. After the thickened mordants have been applied to the fabric and properly fixed, it is necessary to remove the now useless thickening matter, together with the excess of mordant, which has not come into actual contact with the cloth. Formerly a bath formed of cow-dung, diffused through hot water (130° to 212° Fahr.) was always used to wash away these loose matters; but now various manufactured substances are successfully employed for the purpose. The best dung substitutes are the arsenite and arseniate of soda, the silicate of soda, and phosphate of lime. Experience proves that, in the case of these substitutes, a final rinse in cow-dung before dyeing is advantageous. A process very similar to 'dunging' is employed after dyeing, to clear and give purity to the undyed parts. This subsequent process is distinguished by the term 'clearing.' Cow-dung has been used in 'clearing' operations, but its employment is not to be recommended. Bran scalded and mixed with water is employed for certain goods, but bleaching powder is the most generally used 'clearing agent.'

=DUST, ATMOSPHERIC.= When a ray of sunlight is admitted into a dark room, or an electric beam is transmitted through a glass tube, myriads of little motes are revealed, which move and dance about in all directions.

In ordinary daylight these minute particles are invisible. Nevertheless, they are always more or less present in the atmosphere wherever (except under special conditions) this permeates, and they constitute that more or less attenuated, impalpable, generally dry, or dessicated form of matter which we denominate dust.

As with every inspiration we take into our bodies more or less of this suspended material, the study of the composition and characters of the different substances which compose it is one possessed of paramount interest, both for the pathologist and sanitarian.

Amongst solid, inorganic matters found in the open air are silica, peroxide of iron, silicate of alumina, carbonate and phosphate of lime, sand, carbon, chloride of sodium, and metallic iron. These, of course, are of telluric origin, and are carried into the atmosphere by strong currents and winds, which latter have the power of transporting dust to great distances, _e.g._ red sand from the interior of Africa has been found in the sails of ships 600 or 800 miles distant from the African coast, whilst particles of carbon, sand, and dried mud, ejected to great heights from volcanoes into the air, have been transported over still greater distances.

Some doubt appears to prevail as to whether all dust storms originate on the earth, it having been conjectured that some of the solid matters found in the atmosphere may be of meteoric origin, and may have entered it from the realms of space. The chloride of sodium (which the chemist knows is so omnipresent that he cannot heat an ordinary platinum wire in a Bunsen burner without indications of its presence) is derived from the spray of the sea, lifted and diffused into the air by the wind; the iron dust from the rails over which railway trains are constantly passing; the silica, amongst other sources, from the traffic over macadamised thoroughfares.

The organised and organic substances contained in the external air are very numerous. The animal kingdom is the source of the wings of moths, butterflies, and other insects, spiders' legs and webs, hair, wool, epithelium, and eggs, many of these bodies being mere _débris_.

The vegetable kingdom contributes spores, pollen, cells, cotton fibre, and the germs of vibriones and monads. Besides these are many living creatures, brought by the agency of monsoons and cyclones from extensive deserts. Showers of sand derived from these wastes occur in different parts of Europe. Ehrenberg submitted the sand obtained during seventy of these showers to microscopic examination, and found, in addition to sand and oxide of iron, numerous organic forms, amongst which 194 Polygastrica, 145 Phylolithariæ, besides Polythalmia, &c. Silvestre found four species of diatoms and living infusoria in the sand obtained from a dust shower in Sicily in 1872. But, besides the presence of these organisms in the external air, which may be regarded exceptional, it contains, under ordinary conditions, numerous living creatures, some brought into it from the earth by the force of winds, others growing in it. More than 200 forms--rhizopods, tardigrades, and Anguilulæ--have been found in it by Ehrenberg. So tenacious of life are these latter that, even if dried, they will retain their vitality for months, and even years.

Of the organisms found in the air the following are the most important:--1. Extremely small, round, and oval cells, which, that they may be rightly examined by the microscope, require a power of 600 or 1000 diameters. They are found sometimes growing together and sometimes cleaving, when they present an appearance like the figure 8. Sulphuretted hydrogen in the air is said to stimulate their growth and carbolic acid to check it. Although existing in the open air, they are by far more abundant in the atmosphere of dirty prisons. They are also met with in the sweat of the prisoners inhabiting these localities. Observers believe they increase rapidly by cleavage. No ill effects have been traced to them.

"To the same class, perhaps, of these round and oval cells the bacteria and monads, which have been described as gathered from the air, must be assigned; the development of these cells into vibriones and rod-like bacteria, though asserted, has not yet been definitely proved, and, indeed, Burden-Sanderson's observations rather throw doubt on the statement that true bacteria exist in the air.

"2. Spores of fungi are not infrequent in the open air; they occur most commonly in the summer (July and August); they are not in this country more frequent with one wind than another; the largest number found by Maddox in ten hours was 250 spores; on some days not a spore can be found. Maddox leaves undetermined the kind of fungus which the spores developed under cultivation; the spores were pale or olive coloured and oval, probably from some form of smut. Angus Smith found in water through which the air of Manchester was drawn innumerable spores. Mr Dancer has calculated that in a single drop of the water 250,000 fungoid spores as well as mycelium were present; but as the water was not examined for some time there may have been growth. Mycelium of fungus seems uncommon in the air, but is sometimes found.

The cells of the _Protococcus pluvialis_ are not uncommon, neither, perhaps, are those of other algæ. On the whole the experiments of Maddox show that in his locality (near Southampton) it is incorrect to speak of the air being loaded with fungoid spores; they can be found, but are not very numerous."[267]

[Footnote 267: Parkes.]

Amongst other suspended matters are minute fragments of dried horse droppings, derived from the original substance, reduced to powder by the traffic, and carried by aerial currents into the atmosphere. In the 'Chemical News' for October, 1871, Professor Tichborne gives the results of some analyses of the street dust of Dublin. Some dust taken from the top of a pillar 134 feet high contained 29·7 per cent. of organic matter, whilst that collected from the street consisted of as much as 45·2 per cent. This organic matter was principally composed of comminuted stable manure; it was capable of acting as a ferment, and was possessed of deoxidising powers sufficient to reduce nitrate to nitrite of potash.

This evidence of the presence of suspended known matters in the air has led some pathologists to conjecture that certain formless substances found in it, undeterminable by the microscope, may in reality be disease germs, which, being transported through long distances by the wind, may also be the means of spreading certain maladies from one locality to another. In this manner cholera has been supposed to have been propagated from India, the particles of the dried excreta of cholera patients being supposed to be the carriers of the formidable disease; this hypothesis of its origin, however, is not yet, at any rate, universally accepted. "In the case of smallpox and scarlet fever the distance to which the 'contagions' spread by means of the air is certainly inconsiderable."[268]

[Footnote 268: Ibid.]

Hitherto we have spoken only of the nature of the dust occurring in the external air. The composition of that met with in confined spaces is, of course, largely influenced by surrounding conditions and circumstances; for instance, in indifferently ventilated apartments, in addition to the substances already enumerated, the dust of the confined air has been found to contain small particles of food, bits of the hair of human beings, domestic animals, and feathers of birds, as well as of coals, cinders, charred wood, linen, cotton, and wool fibres, varieties of epithelium, and certain round cells resembling nuclei.

In the apartments of the sick it is additionally charged with a very large quantity of organic matter.

The spores of the Tricophyton and Acorion have been discovered in and seem peculiar to skin hospitals. In that taken upon two occasions from the ward of St. Louis (the Skin Hospital of Paris), and submitted to examination, one specimen was found additionally to contain 36 per cent. and in the other 46 per cent. of organic matter.

"The scaly and round epithelia found in most rooms are in large quantity in hospital wards, and probably in cases where there is much expectoration and exposure of pus or puriform fluids to the air the quantity would be still larger."[269]

[Footnote 269: Parkes.]

The investigation of the air of a cholera ward in 1849 by Britain and Swayne, at Clifton, revealed the presence of bodies resembling fungi; minute scales of variolous matter have been found by Bakewell in smallpox wards, and cells of pus and epithelium in the sheds and stables of animals affected with cattle disease and pleuro-pneumonia. Dr Watson detected in the air of a ward for consumptive patients at Netley, together with pus cells, bodies bearing a great resemblance to the cells met with in tuberculous matter, these latter not being discoverable in the open air or in the rooms of non-consumptive persons; whilst Rainy, examining the air of the cholera ward at St. Thomas's Hospital, found bacteria in it, besides fungi. The presence of these bodies was, however, detected in the open air.

The atmosphere of mines, workshops, manufactories, and rooms in which handicraft of any kind is carried on, is more or less laden with small particles of substances employed in the arts, manufactures, and various industries. The nature of these floating substances, as well as a list of the diseases, together with the amount of mortality they produce, will be found under the article "TRADES, CERTAIN, THEIR EFFECTS ON HEALTH."

Dr Wynter Blyth gives the following instructions for collecting atmospheric dust for examination:--

"The most simple way to obtain the emanations from a sick room for microscopical observation is to suspend a common water bottle from the ceiling filled with iced water. The moisture of the air condenses, and brings with it organic matters; or the moisture may be gathered which adheres to panes of glass in cold weather; or a bottle may be taken containing some distilled water, absolutely free from impurities of any kind, and filled several times with the air of the place. The water may then be submitted to microscopical and chemical examination.

"Metallic dust, such as iron, may be attracted by a magnet. The most usual and successful way is, however, by _aspiration_, either by an aspirator made for the purpose [see ASPIRATOR], or by means of an ordinary cask, by which a considerable volume of air is drawn through a small quantity of distilled water, glycerin, or other liquid. The indirect way for the organic matter, &c., mentioned above, viz., analysis of the rain water, and the obvious way of collecting the dust, by carefully sweeping it off shelves, &c., may be also enumerated.

"_Examination of dust._ The dust obtained by any or all of these methods should now be examined microscopically and chemically. Low powers should be used at first, and then (if looking for germs) the highest that can be obtained. If the dust is in any quantity it can be submitted to chemical examination, but a knowledge of what class it belongs to--animal, mineral, or vegetable--is sufficient for most purposes."[270]

[Footnote 270: 'Dictionary of Hygiene.']

=DUST-BIN.= A dust-bin on any premises may become a nuisance and a peril to health if certain precautions are not observed with respect to it.

It should have a tolerably tight-fitting cover, and one that is waterproof also, if, especially as it ought to be, the dust-bin is situated in the open air. The bottom should never be the bare earth, but one that is properly bricked or tiled. It should be lime-washed occasionally, in summer time the most frequently. Only dry refuse, such as ashes and the sweepings of rooms, &c., should be thrown into it.

On no account should fragments of vegetable or animal nature be put in, such as fishbones, potato parings, cabbage stalks, dirty or discarded pieces of apparel, or bits of rags or dusters. These should be at once burnt on the kitchen fire; the best kind of stove for consuming these is that known as the kilnhouse. Meat bones should be got disposed of as soon as possible, as they frequently give rise to unpleasant and offensive odours. Finally, the dust-bin should not be too large. If too capacious, it acts as a guile for servants not to have it cleaned out as often as it should be, the frequent removal of its contents being a most essential condition toward the preservation of health.

=DUSTING.= This very important branch of household labour is sometimes very inefficiently performed. Very frequently the dust of an apartment is not removed, but merely disturbed or driven from one place to settle down on another.

It should always as much as possible be got rid of by means of a duster or a brush and dust-pan.

As the dust should adhere to the former, this should from time to time be taken out into the open air and shaken. During the time a room is being dusted the furniture should be collected in as small a space as possible, and enveloped in the dusting-sheet. The dusting-sheet on its removal should be carefully folded together, taken into the air and shaken. The furniture may then be dusted and returned to the proper places.

A duster should never be rubbed over furniture standing close to a wall, or a dirty mark on the wall-paper will be the result. The same caution applies to mantel-pieces, where the paper may soon be spoilt by the act of dusting, unless contact with the duster be avoided.

=DUTCH DROPS.= The dark-coloured residue left by the dry distillation of turpentine. (Hager.)

=DUTCH GOLD.= See ALLOY.

=DUTCH LIQ'UID.= See OLEFIANT GAS.