120. Diagram of the leaves of Chloranthus inconspicuus and Camellia sasanqua 586 137. Section of a house ventilated and warmed on Drysdale and Hayward's system 138. A slow combustion stove 625 630 139. Plate showing different living vegetable and animal forms found in water 140. Apparatus for estimation of nitrates in water 636 640 MAP OF THE GEOGRAPHICAL DISTRIBUTION OF HEALTH AND DISEASE (by permission, from Keith Johnston's Physical Atlas) To face page 186 DIAGRAM OF THE INTERMITTENT DOWNWARD FILTRATION SEWAGE SYSTEM, as in operation at Merthyr Tydfil (by permission of Mr Bailey Denton) To face page 524 11, col. 2, for "hence 11108 must be added" read "hence 1108 c. c. must be added." 50, col. 2, for "amygdala oleum " read "amygdala oleum." 76, col. 1, 3d line from the bottom of the page, for “at figure 6" read “at figure 9." ,, 120, col. 1, the formula for caramel should be C12H1809. 293, article "Hygiène," after the word "labourer" insert "and." 66 ,, 323, article "Lactin," for or C12H22O11H0" read ". or C12HOHO." 22 11 334, article "Lice," for "especially the pubis" read "especially the pubes." 397, the formula of sinapine in article "Mustard" should be C16H23NO5, and that of "myronate of potash" KC,HNS4019 400, last line in article "Mutual Aid Societies," for "and 1860" read “1860 and 1875." 425, in article "Paraffine," for "a mat or garment" read "sand, earth, ashes, or a mat or garment." ,, 475, col. 2, line 28, for "1844" read "1814." A DICTIONARY OF HYGIÈNE. Abattoir-Abattoirs are public slaughterhouses established in Continental and other towns. The subject is fully considered under SLAUGHTER-HOUSES. and soap. The Ablution - Personal cleanliness is one of the most important habits to inculcate on a people. It cannot be, however, lost sight of, that in order to introduce among the poorer classes habits of cleanliness, a plentiful water-supply and cheap baths are requisite. The amount as well as the nature of the water-supply should be inquired into by every medical officer of health. body should be washed all over every morning with either cold or lukewarm water This custom is more necessary for workmen employed in laborious and dirty occupations than for men of sedentary lives; but all people perspire, and from every drop of perspiration the water evaporates away, and leaves a trace of solid matter on and around the sweat-pores. If this solid matter is not washed off, it accumulates, and may derange the health. It is then well to remember that dirt on the skin does not always come directly from without, but also from within. Cold ablution, that has been so indiscriminately recommended, is not half so efficacious or so safe as lukewarm. The German aurists, struck with the prevalence of deafness in England, ascribe it to our habit of washing the head and ears each morning with cold water. Absinthium-Wormwood-The flowering herb of Artemisia Absinthium; nat. order Composite; indigenous, growing in thickets and mountainous places. It occurs in bundles of the dried herbs, having a silky touch, disagreeable odour, and intensely bitter taste. The plant yields its bitterness to water and spirit, and contains a volatile oil, green in colour, with the odour of the plant; also a bitter extract yielding absinthine (CHO) and absinic acid. The absin thine is the bitter principle. It is omitted now from the British Pharmacopoeia, and its place occupied by the active principle santonine. Absinthe is the name given to an intoxicating drink used largely by all classes of society on the Continent. An analysis recently made at the Conservatoire des Arts shows that absinthe now contains a large quantity of antimony, a poison which cannot fail to add largely to the irritant effects necessarily produced on the alimentary canal and liver by constant doses of a concentrated alcoholic liquid. And we have recently received the results of some experiments made by M. Magnau of Paris. By means of successive distillations he has been able to isolate various products(1) a blue oil; (2) a yellowish oil; (3) an oxygenated product. There was besides a yellowish residue left in the glass. These various substances were tried on animals; ten grammes of the yellow sediment given to a small dog produced no effect; thirty centigrammes (about five grains) of the blue oil produced from eight to ten epileptiform attacks. The oxygenated product proved, however, the most powerful toxic agent. Fifteen centigrammes of it, injected into the veins of a large dog, caused the most violent epileptic attacks, which followed in rapid succession, and ended in death. There was an extraordinary rise of temperature, from 39° Centigrade to 42°, and the post mortem showed various apoplectic centres. Dr. Decaisne regards the terrible evil of this almost universal absinthe-drinking as the greatest national calamity that has ever befallen France, and has made an eloquent appeal to the Government to strike at once a decisive blow at the trade in this liqueur. Originally the only important ingredient in its composition besides alcohol was the essential oil of absinthium, or wormwood; and though this without doubt added something to the mischievous effects of the liquor, it would be impossible to trace to it, or to the other comparatively trivial ingredients, the A 24 more serious of the special results which are now observed to occur to victims of absinthe, though the habitual drinking even in small doses of good absinthe, is believed by Dr. Decaisne sooner or later to produce disorders in the human economy. Now, various deleterious substances are added, the most important of these being antimony. As at present constituted, therefore, and especially when drunk in the disastrous excess now common in Paris, and taken, as it frequently is, on an empty stomach, absinthe forms a chronic poison of almost unequalled virulence, both as an irritant to the stomach and bowels, and also as a destroyer of the nervous system. The effect of absinthe is to produce a superabundant activity of the brain, a cerebral excitement which at first is agreeable; intoxication comes on rapidly; the head swims, and the effect produced is nearly the same as that of poisoning by a narcotic, which certainly does not occur with an equal dose of brandy. With the absinthe-drinker, as with the opium-eater, the excitement the spirit produces diminishes daily in intensity. Each day he is obliged to augment the dose in order to bring himself up to the right pitch. The diseases brought on by the excessive drinking of ardent spirits are produced with greater rapidity by the use of absinthe. The amount of absinthe consumed in London has during the last few years been enormously on the increase. Acarus Farinæ, or Flour - MiteThis insect is found only in damaged flour, and is more frequently met with in the flour of the Leguminosa than that of Graminea. A single acarus may occasionally be found in good flour; but even one should be looked on with suspicion, and the flour should be afterwards frequently examined to see if they are increasing. It differs considerably in structure from the Acarus sacchari. Acarus Sacchari, or Sugar-Mite Found in nearly all the brown sugars of commerce, and is in size so considerable that it is plainly visible to the unaided sight. It may always be detected by the following proceeding: Two or three drachms or teaspoonfuls of sugar should be dissolved in a large wine glass of tepid water, and the solution allowed to remain at rest for an hour or so; at the end of that time the acari will be found, some on the surface of the liquid, some adhering to the sides of the glass, and others at the bottom, mixed up with the copious and dark sediment formed of fragments of cane, woody fibre, grit, dirt, and starch granules, which usually subside on the solution of even a small quantity of sugar in hot water. The Acarus sacchari, when first hatched, is scarcely visible, and first appears as a rounded body or egg. This becomes elongated and cylindrical, until it is about twice as long as broad. After a time the legs and proboscis begin to protrude. The body is partially covered by setæ, and the feet terminate in hooks. In its perfect state its structure is as follows: The body is oval, or rather somewhat ovate, being broader behind than before. From its posterior part four long and stiff bristles proceed, two together on each side, and some eight or ten smaller ones are arranged nearly at equal distances around the circumference of the body. From the anterior part a proboscis of complex organisation proceeds, and from its inferior surface eight legs, jointed and furnished with spines or hairs at each articulation. The spine which issues from the last joint but one of each leg is very long, and extends much beyond the termination of the leg itself. In most samples of sugar the acari may be seen of all sizes, that is, in all stages of their growth, and in every condition. In sixty-nine out of seventy-two samples of sugar examined by Dr. Hassall sugar acari were found. Acarus Siro-Acarus Domesticus, or Cheese-Mite -A very small insect, scarcely perceptible without the aid of the microscope, found in decayed cheese; in fact, the dry and powdery parts of cheese consist almost entirely of these acari and their eggs, in different stages of development. The eggs of this insect are hatched in about eight days. The Acarus siro is furnished with a peculiar elongation of the snout, forming strong-cutting, dart-shaped mandibles, which it has the power of advancing separately or together. They appear to be able to retain life for a lengthened period though deprived of food. Leewenhoek informs us that one lived for eleven weeks gummed on its back to the point of a needle. When kept without food, it is no uncommon sight to see them killing and devouring each other. Cheese is rapidly destroyed by them; they crumble it into minute pieces, and emit a liquid substance which causes the decayed parts to spread speedily. Exposure to a strong heat quickly kills them, or plunging the cheese in whisky will have the same effect. Acetic Acid-See ACID, ACETIC. Acid - The popular everyday signification of this word means anything which is sour to the taste. Scientifically speaking, acids are definite chemical compounds, which unite with alkalies, form bases, and redden vegetable blues. They are now generally considered salts of hydrogen; thus, sul phuric acid (H,SO), hydrochloric acid (HCl), | though the local action is more severe, it is nitric acid (HNO3), are called respectively less extended. the sulphate, the chloride, and the nitrate of hydrogen. In a public-health sense they are chiefly interesting as being emanated in the process of various manufactures, and then acting injuriously both on vegetation and man. Besides this, most of the more common ones are to a degree disinfectants, and many of them have been, by accident or design, used as poisons. The gases evolved from manufactures of alkali used to contain so large a proportion of hydrochloric acid, that it had a most injurious effect on the vegetation of the surrounding district; so much so, that an Act was passed for the more effectual condensation of such gas in alkali-works (26 & 27 Vict. c. 124). This Act, in the first instance, was continued to the 1st of July 1868; but by 31 & 32 Vict. c. 36, s. 1, it has been continued without limitation to time. A section of the Act provides for the appointment of an inspector of such works by the Board of Trade. (See ALKALI ACT.) Now this acid is so effectually condensed that the air emitted from the flues hardly makes a solution of nitrate of silver turbid. The fumes from hydrochloric, sulphuric, sulphurous, nitric, and nitrous acids are quite irrespirable if attempts are made to inhale them in an undiluted form. Diluted well with air, as in some processes for making steel, they appear to irritate the lungs greatly, and have been said to cause pneumonia, bronchitis, and phthisical ulcerations of the tissue of the lungs. Amongst bleachers, and various workers in wool, bronchitis prevails, and the men look sallow and anæmic. This effect has been ascribed to the sulphurous acid disengaged. The effect of acids on vegetation is a subject of practical importance, especially in relation to the question as to whether a manufactory is properly condensing its gases, or whether it is not injuring the surrounding country. The distance at which an acid-emitting manufactory has been found to injure vegetation is about 2187 yards; prevailing winds may, however, carry the vapours farther than this in particular directions; slight undulations in the ground, hedges, walls, belts of trees, and similar obstacles, modify and obviate the action in such a manner as to lead to the conclusion that the gas does not mix uniformly with the air, but is absorbed in small globules of water, which are thrown forward by currents of wind or air, and are driven over any wall or interruption to a distance in a curve from the top.-(ANGUS SMITH.) Rain washes acid gases down to the earth quickly; so that, The effect of acids on the vegetation is to be judged of by the general appearance of the plants, shrubs, and trees in the vicinity. The sources of error in this investigation are numerous, and are more especially due to the fact that dry cold winds, fungi, and insects, produce many spots and changes in leaves and plants similar to those from corrosive vapours. Acids shrivel and curl up the leaves, but do not, like winds, break the stalks, and render them ragged. The coloured spots on the leaves may be tested with litmus paper; but care must be exercised and careful comparisons instituted between the same leaves from healthy plants. Dr. A. Smith says, indeed, that many plants contain chlorides, even on the surfaces of the leaves, at a great distance from alkali-works. Mr. Rothwell affirms that in fields exposed to acid vapours, handfuls of dead grass may be pulled up in the spring, smelling strongly of the vapour, and that trees, under similar influences, become bark-bound. Dr. A. Smith gives, in his work on Air and Rain," the following list of trees, in the order in which they are affected, on Mr. Rothwell's authority:: Forest Trees. 1. Larch. 4. Black Italian poplar. 7. Oak, 8. Elm. 9. Birch. 10. Alder. 11. Sycamore. Shrubs, Evergreens, and Wild Plants. 1. British laurels. 6. Guelder rose. 10. Gooseberries. As well as a 66 Fruit Trees. 1. Damson. 2. Greengage. 3. Halewood plum. 4. Jacob plum. 5. Pears. 6. Apples. 7. Cherries. Farm Crops. 1. Potatoes. 2. Mangel. 3. White clover and rhubarb. 4. Red clover. 5. Trefoil. 6. Rye-grass. 7. Wheat. 8. Oats. 9. Barley. 10. Common turnips. 11. Swedes. |