312 INDUSTRIAL MUSEUMS IN THEIR 



whilst wandering in distant lands. In this volume instructions are 

 given as to the objects worth collecting, and the observations worth 

 making, by those amateurs for whom the work is intended. But natural 

 history iucludes a much wider range of subjects than industrial art, and 

 it should be as easy to instruct travellers how to serve the latter as the 

 former : that it is even more easy, I think will appear from the follow- 

 ing considerations. 



The raw (and other) materials of industrial art are not after all 

 very numerous. Food, clothing, iuel, building-stones, mortars, timber, 

 days, metallic ores, and some other minerals, drugs, vegetable extracts, 

 dye-stuffs, manures, oils, acids, and alkalies, furm the chief material 

 pabulum of intelligent industry. Now even, if we suppose a young man 

 sent with a roving commission to search for all of those materials 

 throughout the world, it would not be difficult to teach him how to 

 recognise each one, at least to the extent of ascertaining to what class it 

 belonged. It would of course be still more easy to equip him intel- 

 lectually for a search for some of them. He could only learn by actually 

 looking at, tasting, touching, and otherwise handling the typical repre- 

 sentatives of the objects which he sought to gather ; but if he laid a 

 foundation in this practical experience, he could afterwards in distant 

 lands widely enlarge it, and be enabled by a guide-book or manual, both 

 to refresh his memory and to extend his knowledge. Thus, in the matter 

 of food, it can be shown ; M. Soyer and all the other culinary authorities 

 concurring ; that the nutritious value of every edible vegetable, root, 

 fruit, seed, or stem, can be ascertained sufficiently well for all great 

 practical purposes, by resolving it, as it always can be resolved, into 

 one class of substances represented by starch, gum, sugar ; and into 

 another represented by the curd-like body called albumen or fibrin, 

 which gives to wetted flour or dough its stickiness. Had this simple 

 test been trusted and applied, Ireland would not have been decimated 

 by the potato famine ; nor, were it believed in at home, would unwise 

 mothers tantalise hungry infants with meagre arrowroot, or unwise 

 farmers, attracted by its cheapness, diet their horses upon sago ; neither 

 would mysterious noblemen advertise their restoration to health through 

 assimilation of costly packets of Revalenta Arabica. 



Again as to fuel. No doubt it is a nice question, What is coal ? anr' 

 somewhat hard to answer ; but there is no difficulty in ascertaining 

 whether a strange body is combustible, and if so, whether it is easily 

 kindled, burns long, burns brightly, gives off much or little smoke, 

 yields a large cinder, and leaves little ash. 



As for cluthing materials, if they are of vegetable origin, the strength, 

 tenacity, softness, lustre, colour, and durability of the textile fibres 

 can be tested by simple and decisive means ; and the hair, wool, or fur 

 of animals is not more difficult to gauge, so far as its textile and felting 

 characters are concerned. The essentials of a good building-stune may 

 be counted on the fingers of one hand, and although prolonged trial 



