Properties of Lard.
—The average properties of different classes of lard in relation to physical and optical conditions are shown in the following table:
| Specific Gravity. 35° C. | Melting Point. ° C. | Refractive Index. 25° C. | Rise of Temperature with Sulfuric Acid. ° C. | Water. Percent. | Iodin Absorbed. Percent. |
|---|---|---|---|---|---|
| .9053 | 40.7 | 1.4620 | 41.5 | .077 | 62.48 |
The above table is the average composition of nineteen samples of lard furnished under affidavits of purity and which appear from their chemical and physical properties to be composed purely of the fat of swine taken from those parts of the animal usually devoted to lard making. The average data may be regarded as representing the properties of the ordinary pure commercial lard on the market.
Average Properties of Steam Lard.
—Below is given the average composition of eleven samples of steam lard furnished under affidavit and, apparently, as judged by their chemical and physical properties, composed solely of the fat of swine. Steam lards are not of as high a quality as the lards contained in the preceding table. They have usually a distinctively strong odor, quite different from that of lards which are rendered in open kettles at low temperature and from selected portions of fat.
| Specific Gravity. 35° C. | Melting Point. ° C. | Refractive Index. 25° C. | Rise of Temperature with Sulfuric Acid. ° C. | Water. Percent. | Iodin Absorbed. Percent. |
|---|---|---|---|---|---|
| .9055 | 37.0 | 1.4623 | 39.9 | .109 | 62.86 |
Properties of Adulterated Lards.
—It is possible to mix together the different materials used in making adulterated lard in such a manner as to produce a compound which in some respects resembles the natural product. This compound, however, necessarily differs from the natural product in its physical and microscopic properties and in its reaction with various chemicals which give distinct color with the different fats and oils used as adulterants. The mean properties of thirteen samples of mixed or compound lards are shown in the following table:
| Specific Gravity. 35° C. | Melting Point. ° C. | Refractive Index. 25° C. | Rise of Temperature with Sulfuric Acid. ° C. | Water. Percent. | Iodin. Percent. |
|---|---|---|---|---|---|
| .9060 | 40.6 | 1.4634 | 46.5 | .098 | 63.58 |