THE CHEMISTRY OF COOKERY. 99 



This is a very fair question, and not difficult to answer. If both 

 are equally cooked, neither over-done nor under-done, they must con- 

 tain, weight for weight, exactly the same constituents in equally di- 

 gestible form, so far as chemical composition is concerned. Whether 

 they will actually be digested with equal facility and assimilated with 

 equal completeness depends upon something else not measurable by 

 chemical analysis, viz., the relish with which they are respectively 

 eaten. To some persons the undisguised fleshiness of the English 

 slice, especially if under-done, is very repugnant. To these the cor- 

 responding morsel, cooked according to Francatelli rather than Mrs. 

 Beeton, would be more nutritious. To the carnivorous John Bull, 

 who regards such dishes as " nasty French messes " of questionable 

 composition, the slice of unmistakable ox-flesh from a visible joint 

 would obtain all the advantages of appreciative mastication and that 

 sympathy between the brain and the stomach which is so powerful 

 that, when discordantly exerted, may produce the effects that are re- 

 corded in the case of the sporting traveler who was invited by a Red 

 Indian chief to a " dog-fight," and ate with relish the savory dishes at 

 what he supposed to be a preliminary banquet. Digestion was tran- 

 quilly and healthfully proceeding, under the soothing influence of the 

 calumet, when he asked the chief when the fight would commence. 

 On being told that it was over, and that in the final ragoiXt he had 

 praised so highly the last puppy-dog possessed by the tribe had been 

 cooked in his honor, the normal course of digestion of the honored 

 guest was completely reversed. 



Reverting to the fat used in frying, and the necessity of its purifi- 

 cation, I may illustrate the principle on which it should be conducted 

 by describing the method adopted in the refining of mineral oils, such 

 as petroleum or the paraffin distillates of bituminous shales. These 

 are dark, tarry liquids of treacle-like consistency, with a strong and 

 offensive odor. Nevertheless, they are, at but little cost, converted 

 into the " crystal-oil " used for lamps, and that beautiful pearly sub- 

 stance, the solid, translucent paraffin now so largely used in the manu- 

 facture of candles. Besides these, we obtain from the same dirty 

 source an intermediate substance, the well-known " vaseline, ^'^ now 

 becoming the basis of most of the ointments of the pharmacopoeia. 

 This purification is effected by agitation with sulphuric acid, which 

 partly carbonizes and partly combines with the impurities, and sepa- 

 rates them in the form of a foul and acrid black mess, known technic- 

 ally as "acid tar." When I was engaged in the distillation of cannel 

 and shale in Flintshire, this acid tar was a terrible bugbear. It found 

 its way mysteriously into the Alyn River, and poisoned the trout ; but 

 now, if I am correctly informed, the Scotch manufacturers have turned 

 it to profitable account. 



Animal fat and vegetable oils are similarly purified. Very objec- 

 tionable refuse fat of various kinds is thus made into tallow, or mate- 



