In the case of clothing this may be done by securely pinning a small piece of white linen to the side of each spot or place from which it is taken, and marking it in ink with a designating letter or figure. Chips of wood cut from the floor or furniture, and other small specimens, should be kept in separate small vials properly labeled. Spots upon weapons may be sufficiently indicated by descriptive notes.

(3) If possible, use only a portion of each stain for the examination. In the case of minute spots the whole may be required for the necessary tests, but in all other cases reserve a part of the material. It may be required for additional tests or further examination in consequence of facts developed during the trial, and possibly the defendant's counsel may desire a portion for the inspection of his own experts. In the latter case deliver nothing except upon a written order of the prosecuting officers. (4) Keep accurate notes of every detail of the examination as it proceeds.

The Appearance of Drops and Direction of Spatters.-Drops of blood from a height of one or two feet are larger than those falling only a few inches. In the first case the circumferences of the spots are deeply indented, but in the second they show a perfectly regular outline. (Fig. 14, a and b.) Spatters indicate their direction by the smaller extremity. This is always farthest from the point of origin (c). An impression of the end of the thumb is represented at d. Drops of blood when examined by the aid of a small hand magnifyingglass show that their edges are slightly raised above the level of the central portion.

The Appearance of BloodStains and of the Substances which resemble them.-The appearance of recent blood, either fluid or in a dried state, upon the surface of cloth, wood, or metals, is so characteristic that it is unlikely that any other substance will be mistaken for it. When, however, the blood is of greater

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age and present only in small spots or stains, and especially upon a dark fabric or surface, it is much more difficult to determine its character.

Small spots upon clothing should be marked by a pin stuck into the cloth near the stain. Unless this is done it will sometimes be difficult to find a given spot when it is again looked for. Considerable time may be saved by attention to this precaution. An ordinary hand magnifying or reading-glass will be found useful for the preliminary inspection. The observer should place the article about to be examined in a horizontal position between his eye and the source of light. The article

should be held at different angles, so that the light may be reflected from the spots somewhat obliquely. Under these conditions blood-stains present a peculiar dark-crimson reflection, which is strongly indicative of blood. Blood-stains, if of any considerable size, upon silk, woolen, or cotton, give a stiffness to the fabric from the drying of the albumen, like that produced by gum; they are glossy and smooth, and have a reddishbrown color. Stains on dark surfaces are best observed by artificial light.

In 1833 a murder was committed in Paris, but the most careful examination of the apartment occupied by the suspected parties, and which was believed to have been the place where the homicide occurred, failed to reveal the slightest appearance of blood. The experts of the government, Ollivier and Pillon, on making further investigation, about eight o'clock in the evening discovered upon the wall-paper a large number of small spatters of a dull red color, which by daylight had the appearance of black points or dots, which were very easily concealed by the design upon the paper; they observed, also, many similar spots on the front of a chest of drawers the wood of which had a deep-brown color. These spots proved to be blood. Other experts, Leseur and Barruel, failed to find the spots on the following day, and were obliged to employ the light of a candle to detect them. (Archives de Médecine, 1833, second series, vol. i.)

Drops or clots of blood upon metals or any hard surface are not adherent, and readily scale off when dry. If the spot is very thin or merely a smudge, it will probably be necessary to scrape it lightly with a penknife if it is desired to remove it.

There are many substances which in small stains look somewhat like blood, but they may, in most cases, be easily distinguished by characteristics peculiar to each.

Iron-rust, Corrosions upon Metals by Lemon Juice, Vinegar, etc.-The appearance of iron-rust varies considerably in its different forms. Some of these closely resemble dried blood. The rust upon iron or steel instruments due to contact with lemon juice, vinegar, etc., has been mistaken for blood.

Orfila mentions the case of a man suspected of murder in whose possession was found a knife apparently covered with blood. A chemical examination of the spots showed that they were due to citric acid. The knife had a few days before been used for cutting a lemon, and had been put away without being wiped.

In the case of rust, its character may be determined by carefully detaching a small portion, putting the same into a porcelain capsule in contact with pure hydrochloric acid, and applying a gentle heat. If the spot be iron-rust, the particles are dissolved and form a yellow solution. A drop of this may be tested by a solution of potassium ferrocyanide, which produces a blue color. Alkalies change the blue color to a reddish-brown precipitate. Another drop gives with solution of potassium sulphocyanide a deep-red coloration. A report by Robin upon the distinctive characters of blood-stains found upon an instrument covered with rust may be found in the Annales de Hygiene, 1859, vol. xii., p. 150. Stains of iron-rust upon linen may be tested in a similar manner. small piece cut from the fabric is boiled with pure hydrochloric acid to form a solution, as in the previous case. A portion of the unstained

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fabric should be similarly tested, since salts of iron are frequently employed as mordants in dyeing and calico-printing.

Extracts of Dye-woods and Tanning Materials.—Various commercial extracts used by dyers and tanners closely resemble dried blood. Among the most common of these are extract of hemlock bark, extract of logwood, cutch, catechu, madder, cochineal and its compounds. All of these are soluble in water, giving brown solutions in the case of logwood, hemlock, cuteh, and similar extracts, and red solutions where madder and cochineal are present. Solutions containing logwood, hemlock, cutch, or other astringent drugs become black upon the addition of a few drops of solution of ferric chloride or of tincture of perchloride of iron. Extract of logwood becomes bright red in presence of the stronger acids. Colors of more or less red shade are derived from Brazil-wood, red sanders, and anatto. Anatto yields an orange-yellow color to water, and is slightly intensified but not changed by ammonia; acids change its color to a red or pink. Most of the red dye colors become crimson or deep red on the addition of ammonia. Madder is changed to a yellow by acids, and on the addition of iron salts becomes brown. All of these colors are bleached by chlorin water, which, unless very concentrated, has no effect upon blood. A case in which blood-stains found upon the clothing of a prisoner were claimed to be catechu, with a report of tests upon the same, is given in Guy's Hospital Reports, second series, vol. vii., p. 413.

Spots of Grease or Tar.-These may be detected by covering the stain by a piece of white filter-paper and pressing with a hot iron, when more or less of the material will be absorbed by the paper. Grease and tar are insoluble in water, but readily dissolve in petroleum naphtha, oil of turpentine, and ether. (See report of a case of this kind in Casper's Forensic Medicine, vol. i., p. 202.)

Fruit, Wine, and other Vegetable Stains.-Such stains do not cause any stiffening of the fiber of the fabric, and they are turned blue or green by ammonia. They are readily distinguished by proper tests, but sometimes have a strong resemblance to blood. Taylor reports a case of this kind. (Medical Jurisprudence, third American edition, p. 217.)

A farmer's boy was arrested on a charge of murder. The blue blouse and trousers which he had worn had on them numerous brown and red stains resembling blood, and appearing to have been produced by the wiping of bloody fingers. The stained articles were subjected to chemical analysis, and it was found that the color was produced by some sort of vegetable juice. The accused stated that the day before his arrest he had collected a large quantity of red poppies which had become bruised by trampling on them, and that he had carried them home in his blouse.

Red Paint.-Dried paint consists of a mixture of oil solidified by oxidation, and a pigment, generally of mineral origin and in red colors, most commonly oxide of iron or red oxide of lead. It is insoluble in water, but on soaking in naphtha, oil of turpentine, or in a strong solution of alkali it is softened and removed. A small portion may be so treated in a watch-glass, in which, after a time, there will be found deposited the mineral pigment, which may be tested for iron as already indicated. Red lead is so different in color from iron that, like vermilion, its appearance is sufficiently indicative of the fact that it is not blood.

In 1840 a person was murdered at Islington. An individual was