This solution is used for testing the following substances:
| British Weights and Measures. | or | Metrical Weights and Measures. | |||||
| Grains weight of substance. | = | Grain- measures of vol. sol. | Grams weight of substance. | = | C. C. of vol. sol. | ||
| Acetum | 445·4 | = | 402 | or | 44·54 | = | 40·2 |
| Acid. acet. | 182·0 | = | 1000 | ” | 18·20 | = | 100·0 |
| Acid. acet. dil. | 440·0 | = | 313 | ” | 44·40 | = | 31·3 |
| Acid. acet. glac. | 60·0 | = | 990 | ” | 6·00 | = | 99·0 |
| Acid. citric | 70·0 | = | 1000 | ” | 7·00 | = | 100·0 |
| Acid. hydrochloric | 114·8 | = | 1000 | ” | 14·48 | = | 100·0 |
| Acid. hydrochloric dil. | 345·0 | = | 1000 | ” | 34·50 | = | 100·0 |
| Acid. nitric | 90·0 | = | 1000 | ” | 9·00 | = | 100·0 |
| Acid. nitric dil. | 361·3 | = | 1000 | ” | 36·13 | = | 100·0 |
| Acid. nitro-hydrochlor. dil. | 352·4 | = | 920 | ” | 35·24 | = | 92·0 |
| Acid. sulph. | 50·6 | = | 1000 | ” | 5·06 | = | 100·0 |
| Acid. sulph. arom. | 304·2 | = | 830 | ” | 30·42 | = | 83·0 |
| Acid. sulph. dil. | 359·0 | = | 1000 | ” | 35·90 | = | 100·0 |
| Acid. tart. | 75·0 | = | 1000 | ” | 7·50 | = | 100·0 |
TE′TANUS. Spasm with rigidity. When it affects the under jaw, it is called TRISMUS, or locked-jaw; when the body is drawn backward by the contraction of the muscles, it is called OPISTHOTONOS; when the body is bent forward, EMPROSTHOTONOS; and when the body is drawn to one side, PLEUROSTHOTONOS.
The cause of tetanus, in temperate climates, is generally irritation of the nerves, arising from local injuries, especially punctured or lacerated wounds. Of these the most trivial are occasionally sufficient to produce locked-jaw. In hot climates the disease is occasionally produced by exposure to cold, or by suddenly suppressed perspiration. The last variety is curable; the former one scarcely ever so. The proper treatment is a matter still undetermined. Sedatives, antispasmodics, and powerful stimulants, have each had their advocates. Large doses of wine and spirits, in conjunction with opium, have occasionally been administered with success. Electricity and the vapour bath have also proved useful. In all cases the bowels should be moved by active aperients, either by the mouth or per anum. Dr Shrimpton[231] recommends the Chinese mode of treating tetanus, which is as follows:—From four to five grains of solid opium are
mixed with tea-leaves, or dried roses, and carefully beaten together with molasses. The patient smokes this mixture, and endeavours to draw the smoke into the lungs, leaving off when the narcotic effects are produced. These last generally from three to four hours. The same operation should be repeated whenever there are any signs of returning spasms.
[231] ‘Lancet,’ 1871, vol. ii, page 547.
TET′TERS. The popular name of several cutaneous diseases, the treatment of which can only be properly undertaken by the experienced medical man.
THAL′LIUM. Tl. [Eng., L.] A heavy metal, belonging to the mercury, silver, and lead group, discovered by Crookes in the early part of 1861, and displayed by him as “a new metallic element” at the opening of the International Exhibition, on the 1st of May, 1862. Thallium is a widely-diffused metal, being found in many minerals, particularly in iron- and copper-pyrites and native sulphur. It has recently been obtained in comparatively large quantities from the dust of the flues leading to sulphuric acid chambers. The spectrum of thallium consists of a single most characteristic line of a beautiful green colour. The spectrum produced when the metal is burnt in the electric arc is, however,
more complicated, and consists of several green, blue, and other lines.
Thallium melts at 550° Fahr., and at a less heat may be readily welded, a property that has hitherto been regarded as peculiar to iron and platinum. Its specific gravity varies from 11·8 to 11·9, according to the mode of preparation. When freshly cut it has a dull white colour, destitute of the brilliancy of polished silver. Exposed to the air, it tarnishes rapidly, a straw-coloured oxide making its appearance on the surface. The oxide is alkaline and caustic to the taste, and much more soluble than the oxides of silver and lead. The metal is remarkable for its strongly marked diamagnetic characters, resembling bismuth in this respect. The alloys of thallium are very remarkable. Copper, alloyed with only one half per cent, of thallium, becomes quite brittle; but the alloy with tin is malleable. Mr Crookes has prepared a great number of the salts of this interesting metal. These need not be described here, as they have not yet been applied to any use in the arts. See Sulphuric acid.