Equipment necessary for first aid treatment of snake bite includes a sharp cutting instrument such as a razor blade or sharp knife for making incisions, a constricting band to retard the flow of lymph, iodine or alcohol for sterilizing the knife and bitten area, and a suction device for removing the venom-contaminated lymph. This last item is especially important if you are alone and cannot reach the wound to apply suction by mouth. Snake bite kits containing the essential items can be purchased at most drug or sporting goods stores at a cost of from two to five dollars, depending upon the make. Anyone who spends much time outdoors should carry a snake bite kit at all times, and he should know how to use it. A smaller kit can be more easily carried and is less likely to be left at home or in the car. DIAGNOSING THE BITE To make certain that a poisonous snake has caused the bite, first examine the wound for teeth marks. In a perfect bite by a poisonous snake (excluding the coral snake), the pattern will reveal two distinctly larger holes where the fangs have entered the flesh. There also may be two rows of smaller teeth marks between these punctures. [Illustration: Snakebite patterns] Furthermore, if the snake engages the lower jaw, two additional rows of small teeth impressions will be seen below the first group. Frequently the bite pattern is not a clear one. For example, if the snake pulls to one side as it disengages the fangs after a strike, the result is a series of scratch marks instead of punctures. There is also the possibility that the snake will engage only a single fang; or, perhaps, during fang replacement, two fangs are temporarily in position on one or both sides of the upper jaw. Any of these conditions, as well as others, can contribute to an obscure bite pattern. The bite of a coral snake often is difficult to diagnose by examination of the wound. Because this snake impels its fangs in a sort of chewing motion, the pattern created by its bite may be two groups of closely spaced punctures where the fangs have entered the flesh a number of different times. A clearly defined harmless snake bite pattern consists of a series of uniformly small punctures (four rows made by teeth in the upper jaw, two rows by teeth in the lower), but always without the large fang holes. More typically, a non-poisonous bite produces several rows of scratches. Pit-viper poisoning is diagnosed primarily by the presence of _local_ signs and symptoms. The most important of these are: 1. _Pain_ accompanies most poisonous snake bites. Generally intense and burning in character, it becomes more severe with the passing of time. This symptom alone is not conclusive because pain can be imagined following a non-poisonous bite. Occasionally in a severe bite, the pain is replaced by numbness and tingling.