1361. Amount of Heat to be Employed in Making Syrups

1361.    Amount of Heat to be Employed in Making Syrups. In the preparation of syrups it is of great importance to employ as little heat as possible, as a solution of sugar, even when kept at the temperature of boiling water, undergoes slow decomposition. The best plan is to pour the water (cold) over the sugar, and to allow the two to lie together for a few hours, in a covered vessel, occasionally stirring, and then to apply a gentle heat, preferably that of steam or a water-bath, to finish the solution. Some persons (falsely) deem a syrup ill prepared unless it has been allowed to boil well; but if this method be adopted, the ebullition should be only of the gentlest kind (simmering), and should bo checked after the lapse of ono or two minutes. "When it is necessary to thicken a syrup by boiling, a few fragments of glass should bo introduced, in order to lower the boiling point. In boiling syrups, if they appear likely to boil over, a little oil, or rubbing the edge of the pan with soap, will prevent it. Syrups are judged by the manufacturer to bo sufficiently boiled, when some taken up in a spoon pours out like oil; or, a drop cooled on the thumb nail gives a proper thread when touched. (See No. 1368 (Degrees of Boiling Sugar).) When a thin skin appears on blowing upon the syrup, it is judged to be completely saturated. These rude tests often lead to errors, which might be easily prevented by employing the proper proportions, or determining the specific gravity.

1362. Table of Specific Gravities of Syrups

1362.    Table of Specific Gravities of Syrups.

The degrees of Baum'e here given are those of his heavy saccharometer. ___ ___

The latter density is about the syrupus of the pharmacopoeias; that of the IT. S. Ph. has a sp. grav. 1.317; that of the British Ph. is 1.330.