The specific gravity corresponding to any degree of the scale, may be calculated in the absence of a table giving it, by the following formula 144.3 _P_ = -----------. 144.3 - _d_ In this formula _P_ is the density and _d_ the degree of the scale.[30] In former times the baumé instruments were graduated with a solution of common salt and a different formula was employed for calculating specific gravity, but these older instruments are no longer in common use. The following table shows the specific gravities of solutions corresponding to baumé degrees from 1° to 75° consecutively[31]: Degree Specific Degree Specific Degree Specific Degree Specific baumé gravity baumé gravity baumé gravity baumé gravity 0 1.0000 19 1.1516 38 1.3574 57 1.6527 1 1.0069 20 1.1608 39 1.3703 58 1.6719 2 1.0140 21 1.1702 40 1.3834 59 1.6915 3 1.0212 22 1.1798 41 1.3968 60 1.7115 4 1.0285 23 1.1895 42 1.4104 61 1.7321 5 1.0358 24 1.1994 43 1.4244 62 1.7531 6 1.0433 25 1.2095 44 1.4386 63 1.7748 7 1.0509 26 1.2197 45 1.4530 64 1.7968 8 1.0586 27 1.2301 46 1.4678 65 1.8194 9 1.0665 28 1.2407 47 1.4829 66 1.8427 10 1.0744 29 1.2514 48 1.4983 67 1.8665 11 1.0825 30 1.2624 49 1.5140 68 1.8909 12 1.0906 31 1.2735 50 1.5301 69 1.9161 13 1.0989 32 1.2849 51 1.5465 70 1.9418 14 1.1074 33 1.2964 52 1.5632 71 1.9683 15 1.1159 34 1.3081 53 1.5802 72 1.9955 16 1.1246 35 1.3201 54 1.5978 73 2.0235 17 1.1335 36 1.3323 55 1.6157 74 2.0523 18 1.1424 37 1.3447 56 1.6340 75 2.0819 =55. Correction for Temperature.=—The baumé hydrometer should be used at the temperature for which it is graduated, usually 15°. In this country the mean temperature of our working rooms is above 15°. The liquid in the hydrometer flask should therefore be cooled to a trifle below 15°, or kept in a bath exactly at 15° while the observation is made. When this is not convenient, the observation may be made at any temperature, and the reading corrected as follows: When the temperature is above 15° multiply the difference between the observed temperature and fifteen, by 0.0471 and add the product to the observed reading of the baumé hydrometer; when the temperature on the other hand, is below fifteen, the corresponding product is subtracted.[32]