[THE HOUSEWIFE’S ROOM.]
This apartment should represent in the household the important place occupied by the laboratory in a manufactory. In it should be found the necessary means of examining the qualities of the various articles consumed in the household, and of combating the evils which surround the inmates. This statement presupposes a wide knowledge on the part of the housewife, who, indeed, is often expected to know more than many professors—hence the value of a book like the present as a guide. For facility of reference, the main facts useful to the housewife in her daily duties, i.e. facts which she is particularly called upon to know outside the ordinary routine of cooking and housework, will be grouped together in sections.
Testing
Testing.—Chemistry is a valuable science, and more fully appreciated every day in its application to home matters; but the average housewife cannot be expected to qualify herself as an analyst. At the same time there are many simple tests for the purity of air, water, and foods that can easily be brought within the range of an ordinarily intelligent woman, and will be found of great service.
Air.—Apart from poisonous gases due to sewers, &c., there is a constituent of air, which, in excess, becomes poisonous also. This is carbonic acid. Wholesome air does not contain more than 5 volumes of carbonic acid in 10,000; as the proportion increases, the quality of the air deteriorates till it becomes actively poisonous. The simplest method of estimating approximately the proportion of carbonic acid present in the air of a room is by shaking up a small quantity of lime water with a certain amount of the air to be tested. The lime water is prepared by shaking slaked lime with distilled water, allowing it to settle, and then carefully drawing off the clear liquid by a siphon, so as not to disturb the sediment. It can be obtained from any druggist, but should be freshly made.
When this lime water is shaken up in a bottle of air containing carbonic acid, the acid combines with the lime, forming an insoluble powder of carbonate of lime, and when this is in sufficient quantity it makes the water turbid, or milky, so that it can be recognised by the eye. By having a series of bottles of various sizes, filling them with the air to be tested, placing in each bottle a large tablespoonful of lime water, and then shaking them vigorously for 3 or 4 minutes, so that all the air in the bottle shall be brought in contact with the lime water, and all the carbonic acid be taken up by the lime, we shall find that in one bottle of the series the turbidity is just perceptible, while in bottles of less size the fluid remains clear, and in those of greater size it is dense.
The following table is given by Dr. Smart as expressing the relation between the size of the bottle in which turbidity occurs and the volume of carbonic acid in the air:—
| Size of Bottle in fluid ounces. | Carbonic Acid in volumes per 10,000 air. | Size of Bottle in fluid ounces. | Carbonic Acid in volumes per 10,000 air. |
| 20.6 | 3 | 5.5 | 12 |
| 15.6 | 4 | 5.1 | 13 |
| 12.5 | 5 | 4.8 | 14 |
| 10.5 | 6 | 4.5 | 15 |
| 9.1 | 7 | 3.5 | 20 |
| 8.0 | 8 | 2.9 | 25 |
| 7.2 | 9 | 2.5 | 30 |
| 6.5 | 10 | 2.0 | 40 |
| 6.0 | 11 | ||