United States Sanitary Commission bulletin.

Date:
1866
Catalogue details

Licence: Public Domain Mark

Credit: United States Sanitary Commission bulletin. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    acter of the water. In the field it is fre- quently impossible to camp troops in posi- tions which afford good drinking water, but in the location of hospitals and permanent works this end can generally be insured. It should be recollected that no one sanita- ry element is of more importance than the one under consideration. I have known stations selected without the least regard to the character of the water; where this was so loaded with saline matters that the men were almost constantly affected with diarrhoea, or so contaminated with organic substances that putrefaction commenced in a few hours after it was brought to the quarters. * * • * * Organic matters are frequently present in water, and give it qualities which ren- der it deleterious. They may be either gaseous or morphological, as portions of decomposing vegetable or animal remains, infusoria, algae, fungi, etc. Water in which such matters are found readily be- comes putrescent, and is most noxious to the health of those who use it as a drink, producing diarrhoea and fever. * * Examination of Drinking Water.—By ascertaining the specific gravity of the water to be tested, a rough idea of the quantity of solids contained in it can be obtained. Kirwan gives the following formula for this purpose, which he states will generally indicate the proportion with- in one or two per cent. Deduct from the specific gravity of the water the number 1000, and multiply the difference by 1-4, the product will represent the quantity of solid contents. It gives the weight of the salts in their most desic- cated state, and consequently freed from their water of crystallization. The weight of fixed air must be also included. Thus, if the water under examination possess a specific gravity of 1015, the 1000 subtracted from this sum leaves 15, which multiplied by 1-4, gives 21, the number of parts of solid matter in 1000 parts of the water. A better plan is to evaporate to dryness a certain amount of water, and to weigh the solid residue. Sulphuric acid is most readily detected by solution of chloride of barium, by the action of which a heavy white precipitate of sulphate of baryta is produced. Ghlorhydric acid is indicated by solution of nitrate of silver, by which a flaky pre- cipitate of chloride of silver, soluble in liquor ammonite, is thrown down. Sulphuretted hydrogen, if present, forms, with, solution of acetate of lead, a brown precipitate of sulphuret of lead. In water containing lead, sulphuretted hydrogen, when passed through it, gives a like precip- itate. Lime gives, with oxalate of ammonia, a white precipitate of oxalate of lime. Magnesia is indicated by liquor ammonise, which separates it as a light flaky precipi- tate. Iron forms, with tincture of galls, a black precipitate of tannate of iron; with ferrocyanide of potassium, a dark-blue precipitate of ferrocyanide of iron is formed. Organic Constituents.—The organic con- stituents of water when not in solution are readily detected by means of the micro- scope. Organic matters, when in solution, can be most satisfactorily discovered by means- of solution of permanganate of potassa. This salt gives a bright-red color to the distilled water in which it is dissolved, which hue is entirely removed on sub- jecting it to the action of organic matter. We have thus a valuable means of detect- ing impurities which, would otherwise es- cape observation. The method of pro- ceeding is very simple. A drop of satu- rated solution of permanganate of potassa, or of Condy’s disinfectant fluid, (which consists of a solution of alkaline perman- ganates,) added to a half pint of distilled water, gives to it a beautiful pink color, which will remain permanent for a long time; but if the same quantity be added to any ordinary drinking water, the per- manganate is decomposed by the organic matter present, and the characteristic color is destroyed as soon as found. If there be much organic matter present, more of the solution will be required to produce any color at all; and, by the quantity used to cause the formation of a perma- nent pink tinge, we draw our conclusions relative to the purity of the water examin- ed. The presence of minute particles of organic matter is also readily indicated by this reagent. * * * * BATTLE OF GETTYSBURG. [From Prof. Jacob’s Eebel Invasion of Maryland and Pennsylvania.] This battle of three days will compare in magnitude and far-reaching consequences, with any of the great battles of modern times. In the battle of Waterloo, the Allies had 72,000, the French 80,000 men; in this the rebels had 90,000, the Federals about 60.000 men. The British had 186 cannon, the French 252; the rebels had upwards of 200, and we an equal number. The Allies lost 20.000 in killed and wounded; the French 40.000 in killed, wounded, prisoners, and deserted; the Federals lost about 4,000 killed, 12,000 wounded and 4,000 prisoners, or in all about 20,000; whilst the rebels lost 5,500 killed, 21,000 wounded, and 9,000 prisoners and 4,000 stragglers and deserters, or a total of about 40,000. The proportion of men and of losses in both battles is near- ly the same.
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