Hair test 70s of this century, an arsenic poisoning of Napoleon died of massive news shocked France and the United Kingdom confirmed the frule that the distinctive; basis is to preserve a 100 years of Napoleon Beam hair. Some people were radioactivityive content of Napoleon's hair analysis, concluded that Napoleon was imprisoned on St. Helena, the British period, guards often cast arsenic in his food, and this causes chronic arsenic poisoning. The news was discclosedownd, a dispute about the cautilize of death of Napoleon, between the French and British launched fierce. French people pointing their accusing fingers, insisted that their leader and hero of the British poisoned , while the British were denied, said the manufactureatory analysis of the results of Napoleon's hair is erroneous, the arsenic content of hair of Napoleon is not permitted beyond the normal range. Ever beam as the sole basis that unfortunate hair, and I never no peace, again and again to be brought for testing, and the consequence is the eyes of the beholder, the wise see wisdom, and had to let the matter rest. In this case, the bunch of little hair, light the dispute between the two countries \is easy to fall off and not easily characterized by corruption, which is a common crime scene evidence on one. a very humble hair, criminals often judge our sex, age, blood type, occupation and nature of the case, modus operandi and modus tools and other significant basis. body surface, in addition to the palm, paw, in general, have hair growth.'s hair from the first three months of fetal growth, the first four months over the entire body can be. human hair according to the thickness of the different soft and hard, is divided into two kinds of soft and hard hair. soft hair, called hairs, valuables and pale, over the surface of the skin. hard hair rough and hard, growth in certain parts of the body, such as hair , eyebrows, eyelashes, beard, nose hair, armpit hair, chest hair, pubic hair and so on. different races, ethnic, gender and age, as well as different individuals, different parts of the same individual, the hair is different. However, for now technical testing standards, and also can identify the type of hair, hair can not be identified for a specific individual all. hair can be divided into hair root, hair shaft and tip-of three parts. the hair shaft is exposed outside the skin part of it from the inside out can be divided into medulla, cortex and hair cuticle layer; hair known as the tip-most tip; buried in the inside part of the skin called the hair root. the bottom of the root hair swelling spherical, called Mao ball. wrapped around the hair root hair root of the skin, called follicles. hair growth to a certain period of time, they start off and replacement. human hair replacement, unlike mammals, the seasonal molt, but life often continue to off gradually replaced. According to statistics, people's hair, 10 ~ 200 000, head 8 140 000, trunk and extremities 20 000, 30 ~ 120 a day off. different parts of the hair, the length of its life not the same, hair long life 2 to 5 years, 2 to 3 years beard, armpit hair 1 to 2 years, pubic hair 1 to 1 ? years (some say his beard, armpit hair,ghd i, pubic hair life span of only 7 to 10 months), eyebrows , eyelashes life 3 to 5 months. hair loss than life outside the natural expiration, but also due to poisoning, disease or violence, the role of loss. hair test can usually address the following issues: 1. is the hair hair or other fibers addition, the outside world have a similar shape and hair of all natural fibers and synthetic fibers. hair testing, we must first address whether the hair samples problem. hair and other identifying fiber, can be distinguished from the histological up. hair is not unique the shape, color, flexibility, and other fibers are different, and hair that has the hair cuticle, cortex and medulla of the three-tier structure, it is not the other fibers. also can distinguish between the solubility of samples. hair easily dissolved in 19% potassium hydroxide or hydrogen chloride solution, while other fibers are not dissolved in this solution. In addition, the hair burning will release a special smell, no burning the general fiber release this particular smell, although the combustion of synthetic fibers with special smell, but it is easy to distinguish the smell with the hair. 2. is a human or animal hair human hair and animal hair hair notwithstanding some similarities, but their morphology and so on have their own characteristics, a close inspection, the general is not difficult to identify. From hair cuticle of view, human hair hair cuticle scales thin, outer edge finely serrated, surface patterns small and irregular varyment. On the contrary, animal hair in the hair cuticle scales thick, coarse outer edge was jagged surface pattern relatively thick, straight, lined . from the cortex of scenery, human hair cortex wide, pigment particle size and distribution more uniform, less pigment Maojian Department; and animal hair's cortex is relatively narrow, pigment granules of various sizes, uneven distribution of Maojian Department have more pigmentation. scene from the medulla, the medulla of human dermal hypoplasia, narrow, uneven, was intermittent-like changement; and animal hair in the medulla well-developed, wide, uniform No interruptions. people long soft hair, a hair generally show a color. In contrast, the fur is fleeting and rugged, a number of hair colors can be presented. In addition, agar diffusion method can be used to distinguish a human hair or animal hair. the hair roots into agar plate, if the agar plate against human serum precipitation reaction, that is, that is human hair samples. 3. what parts of the body hair samples to determine is when human hairs, also need to determine which parts of the body hair. different parts of the body hair, such as hair, eyebrows, eyelashes, nose hair, armpit hair, pubic hair, etc., the length, thickness, color , shape, cross-sectional features and attachments, etc. have a certain degree of difference, which is also not difficult to distinguish between them. (1) hair: the longest is the person's own hair, the average diameter of 0.075 ~ 0.1 mm , black, dark brown or gray. hair according to its shape can be divided into straight hair, wave hair, and curly hair into three categories, each of which can be divided into several subtypes. Chinese human hair, usually straight hair, it is infrequent wave of hair and curly hair. hair were round or oval cross section may have grease, hair color, etc. attached. hair medulla often appear discontinuous or absent, cortical pigment granules more uniform in size and distribution.