MODERN USES OF THE METAL ALUMINIUM 623 



Household and Travelling Utensils 



In discussing the application of aluminium to household 

 purposes, travelling and military equipments, properties of the 

 metal have to be considered which are of no account in the 

 cases previously considered. The use of the metal for such 

 purposes depends in the first instance upon the fact that com- 

 pared with the materials heretofore used in kitchen and camp, 

 aluminium is either infinitely safer from a hygienic point of 

 view or far more durable. In this case, comparison lies 

 between aluminium on the one hand and iron, copper, enamelled 

 iron and tinned iron on the other. For heavy cooking utensils, 

 such as large kettles and heavy pans, iron still holds the field. 

 Iron vessels, however, can be used only for a very limited 

 number of purposes and are unsuitable for general use owing 

 to the difficulty of keeping them clean and free from rust and 

 the coloration and taste they impart to food. Their thermal 

 properties also render them unsuitable for fine cookery. 



Copper cannot be used safely owing to the solubility of 

 copper in the weakly acid materials contained in foodstuffs 

 and the fact that copper salts are most active poisons. Copper 

 vessels, therefore, are coated with a thin layer of tin. This 

 precaution is by no means sufficient to eliminate the danger, 

 because the tin, sooner or later, wears off. Moreover, the cost 

 of copper vessels is more than the purse of most housewives 

 can bear and the cost of retinning is a permanently recurring 

 charge. In point of price, aluminium cannot bear comparison 

 either with tinned or enamelled iron but the life of the former 

 is so very short that it does not form a serious competitor 

 Enamelled iron may and frequently does give satisfaction on 

 this score ; on the other hand, it is entirely untrustworthy 

 and in case of damage to the enamel it is the most dangerous 

 material which can be used. There is in this case no question 

 of poisoning as with copper but chips of enamel become inter- 

 mixed with the food and probably are the cause of oisorders 

 such as appendicitis, etc., more frequently than is supposed. 

 From all these disadvantages aluminium is absolutely free. 

 Drawbacks of its own it has but these are distinct from those 

 cited above. Aluminium is second only to copper among the 

 common metals in thermal conductivity and gives no colour 

 to the finest materials. Dirt is seen so easily upon its white 



