Professor Wanklyn gives the following
formulæ for the preparation of the Nessler test:—Mercuric chloride in powder, 35 grammes; iodide of potassium, 90 grammes; water, 13⁄4 litres; heat gently till dissolved (say 20 minutes) in a large basin. Then add of stick caustic potash, 320 grammes, and 50 c.c. of saturated solution of mercuric chloride. The above will be ready for use in 2 hours, and gives maximum colour in 3 minutes.
NESTS, EDIBLE. These dietetic curiosities, which are esteemed as great gastronomic luxuries by the Chinese, are formed by several species of swallows frequenting the Indian Seas. The so-called nests chiefly abound in Java, Borneo, and the Celebes, being found in the caverns both inland and on the sea-shores of those islands.
They are not in reality birds’ nests, but merely supports, by which the bird is enabled to sustain and also to attach its nest to the rock. The nests themselves consist of grass, leaves, and seaweed; the latter of which substances it was for a long time erroneously considered formed the esculent; whereas it is the support which exclusively constitutes this Eastern table luxury.
This, in great part, consists of a peculiar mucus, of a gelatinous nature, which it has been ascertained the bird secretes and discharges from its mouth in large quantities. The Chinese mostly use it in the form of soup, and believe it to be possessed of considerable nutrient power. As many as 8,400,000 of edible nests are said to be annually imported into Canton. “The finest and whitest kind sells for £5 or £6 the lb.; but it requires about fifty nests to make up one pound. The brackets or supports are moved three times, the best being obtained in July and August.”[44]
[44] Church.
NET′TLE RASH. See Rash.
NEURAL′GIA. Literally, pain in a nerve. “Various parts of the body are liable to be affected with excruciating pain, which is quite independent of any inflammation of the part, and which may often be traced in the course of the nerves.” These affections constitute neuralgia. One of the most distressing forms of this disease is FACIAL NEURALGIA or TIC DOULOUREUX (NEURALGIA FACIALIS), which, when it assumes a marked intermittent character, is popularly known as ‘FACE AGUE,’ Sometimes it attacks the nerves of the female breast; or those of the hand, feet, hip, or loins, in which cases it is often confounded with acute rheumatism of those parts, occurring towards the inner extremity of the eyebrow and extending over the forehead, it is known as “Brow-ague.”
The treatment, when neuralgia is symptomatic of any other affection, must be directed to the primary disease. When it is idiopathic, or an independent affection, powerful tonic medicines and powerful local counter-irritation are generally found the most successful remedies. Of tonics, carbonates of iron and bark
(both in very large doses) are generally preferred; the last more particularly when the affection is of an intermittent kind. As a counter-irritant, caustic ammonia has been much relied on. When all other means fail, a current of mild streaming electricity through the part will often give immediate relief. In the present day quinine in large doses is much depended on, although the affection should not present the intermittent type.