I add by way of postscript a recipe for a dish lately invented by my wife. It is vegetable marrow au gratin, prepared by simply boiling the vegetable as usual, slicing it, placing the slices in a dish, covering them with grated cheese, and then browning slightly in an oven or before the fire, as in preparing the well-known ‘cauliflower au gratin.’ I have modified this (with improvement, I believe) by mashing the boiled marrow and stirring the grated cheese into the midst of it whilst as hot as possible; or, better still, by adding a little of the solution of cheese above described to the purée of mashed marrow and stirring it well in while hot. To please the ladies, and make it look pretty on the table, a little more grated cheese may be sprinkled on the top of this and browned in the oven or with a salamander. People with weak digestive powers should set aside the pretty.
Turnips may be similarly treated as ‘mashed turnips au gratin.’ I recommend this especially to my vegetarian friends, who have no objection to cheese, but do not properly appreciate it.
Taking as I do great interest in their efforts, regarding them as pioneers of a great and certainly approaching reform, I have frequently dined at their restaurants (always do so when within reach, as I am only a flesh-eater for convenience’ sake), and by the experience thus afforded of their cookery, am convinced that they are losing many converts by the lack of cheese in many of their most important dishes.
[CHAPTER X.]
FAT—MILK.
We all know that there is a considerable difference between raw fat and cooked fat; but what is the rationale of this difference? Is it anything beyond the obvious fusion or semi-fusion of the solid?
These are very natural and simple questions, but in no work on chemistry or technology can I find any answer to them, or even any attempt at an answer. I will therefore do the best I can towards solving the problem in my own way.
All the cookable and eatable fats fall into the class of ‘fixed oils,’ so named by chemists to distinguish them from the ‘volatile oils,’ otherwise described as ‘essential oils.’ The distinction between these two classes is simple enough. The volatile oils (mostly of vegetable origin) may be distilled or simply evaporated away like water or alcohol, and leave no residue. The fixed oils similarly treated are dissociated more or less completely. This has been already explained in [Chapter VII.]
Otherwise expressed, the boiling point of the volatile oils is below their dissociation point. The fixed oils are those which are dissociated at a temperature below their boiling point.