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THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



in the form of gas, which had only been possible 

 before with the fluids and solids ; and when an 

 exact balance had been struck, it appeared that, 

 at any rate among the carnivora and man, fat is 

 never produced by the hydrocarbons, not even 

 when taken in the greatest quantity, but that it 

 must be produced by the fat in the food and by 

 being eliminated from albumen. Voit, by his 

 experiments on a milch-cow, has rendered the 

 production of fat by hydrocarbons in the herbiv- 

 ora very doubtful; and we are thus compelled 

 to conclude that all fat not contained in the food, 

 which is produced in the body, has its origin in 

 the decomposition of albumen, and that the hy- 

 drocarbons, previously looked upon as fat-form- 

 ers, only serve to prevent the fat originating in 

 albumen from combining with oxygen, from fur- 

 ther decomposition into carbonic acid and water, 

 from so-called combustion. No single experi- 

 ment since made has contradicted this theory ; 

 indeed, time has only confirmed it. Liebig never 

 could reconcile himself to it ; he even disputed it 

 in his last work on fermentation and muscular 

 force ; but this does not detract from his great 

 services on the question of alimentation, for even 

 the modern view is but the result of the impetus 

 which he gave to it. 



Closely connected with food are Liebig's ex- 

 periments on meat, which first gave us a precise 

 idea of the chemical composition of muscle, by 

 far the largest and most solid part of our bodily 

 elements. One fruit of these studies is the ex- 

 tract of meat, which has been so much discussed, 

 and as much overrated as underrated. Without 

 granting that one ounce of the extract is equal to 

 a pound of meat, or that you may turn bread into 

 meat with it, it was a valuable gift to mankind ; 

 it has been found a welcome cordial to the travel- 

 er in the desert, the voyager to the north-pole, 

 and our soldiers in war, and it finds a place more 

 and more in the kitchens of the middle class. 

 Among the luxuries which are necessary additions 

 to our food, none is more grateful than soup, and 

 we have the essential basis of it, only in another 

 form, in extract of meat. Liebig occupied him- 

 self much with the physiological value of this 

 protege of his, which has become so large an 

 article of trade. 



On the whole, Liebig initiated and rendered 

 possible a science of nutrition. It is a curious 

 fact that his ideas have been much more tardy 

 in making their way into the laboratories of ani- 



mal and vegetable physiology than into the ex- 

 perimental agricultural stations which he also in- 

 stituted, and which have proved so useful. Though 

 their chief aim is practical, they sometimes con- 

 tribute to the advancement of science. Farmers 

 now go deeply and successfully into the question 

 of the best means of feeding and fattening vari- 

 ous races of animals. It might be no less to the 

 advantage of the human race if experiments were 

 tried as to the best diet for the various classes of 

 our population. 



I am well aware that I have by no means ex- 

 hausted the subject of Liebig's achievements in 

 science, but have simply indicated them ; what I 

 have said suffices to show how great they were, 

 even though all that he did, wrote, and said, was 

 not free from human error and weakness. We 

 will not desecrate his memory by flattery or ser- 

 vile adulation — 



"Es irrt der Mensch so lang er strebt." 



If in some things Liebig did not entirely suc- 

 ceed, if he did not finish everything that he under- 

 took, he only shared the fate of the greatest men 

 in history, and other benefactors of mankind, but 

 he none the less influences the present and the 

 future. Let us rejoice in the inheritance he has 

 left us. It is distinguished from all earthly pos- 

 sessions by this peculiarity, that every one may 

 take of it as much as he will without lessening the 

 store for the rest; nay, the more every one makes 

 it his own, the more will it increase and multiply. 



It is an old and familiar metaphor, derived 

 from the most ancient department of practical 

 chemistry, the production of metals, advance in 

 which divides one great epoch of civilization from 

 another, that every man may be looked upon as 

 an alloy of base and precious metals, that he 

 must be tried and purified in the fires of life and 

 of death, and that the more he has aspired after 

 noble ends in life the more precious will be the 

 residuum that he leaves. Every man who has 

 honestly pursued noble ends, leaves behind, as 

 the flame of life expires, a grain, smaller or larger, 

 of precious metal ; few only are utterly consumed 

 as dross in the fiery furnace of this life, but the 

 weight of the residue greatly varies. Liebig now 

 lies, as it were, before us on the burning, refining 

 hearth of a ceaselessly active and noble life — a 

 mighty deposit of silver which coming generations 

 may yet gaze on with admiration. — The Contempo- 

 rary Review. 



