C: 



THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



for many ages by the best teaching of English- 

 men, and — what is far more important — by the 

 best practice of Englishmen, yet it cannot be 

 accepted on a large scale without what will seem 

 to many a decline of religious belief. For as- 

 suredly if men learn the nature of God from the 

 moral sense of man, they cannot go on believing 

 the doctrines of popular theology. Such change 

 of belief is of small account in itself, for any 

 consequences it can bring about; but it is of 

 vast importance as a symptom of the increasing 

 power and clearness of the sense of duty. 



On the other hand, there is one " decline of 

 religious belief," inseparable from a revolution in 

 human conduct, which would indeed be a fright- 

 ful disaster to mankind. A revival of any form 

 of sacerdotal Christianity would be a matter of 

 practice and not a matter of theory. The system 

 which sapped the foundations of patriotism in 



the old world; which wellnigh eradicated the 

 sense of intellectual honesty, and seriously weak- 

 ened the habit of truth-speaking ; which lowered 

 men's reverence for the marriage-bond by placing 

 its sanctions in a realm outside of Nature instead 

 of in the common life of men, and by the institu- 

 tions of monasticism and a celibate clergy ; 

 which stunted the moral sense of the nations by 

 putting a priest between every man and his con- 

 science — this system, if it should ever return to 

 power, must be expected to produce worse evils 

 than those which it has worked in the past. The 

 house which it once made desolate has been par- 

 tially swept and garnished by the free play gained 

 for the natural goodness of men. It would come 

 back accompanied by social diseases perhaps 

 worse than itself, and the wreck of civilized Eu- 

 rope would be darker than the darkest of past 

 ages. — Nineteenth Century. 



LIEBIG'S SCIENTIFIC ACHIEVEMENTS. 



By Prof. MAX VON PETTENKOFER, Professor of Hygiene in the University of Munich. 



LIEBIG was one of those happy but excep- 

 tional individuals who feel their future 

 course marked out for them by Nature from their 

 earliest days. When at the gymnasium at Darm- 

 stadt, he had so decided a predilection that, when 

 asked by his professor how he employed himself 

 out of school-hours and what he meant to be, he 

 at once answered, " A chemist." Soon afterward, 

 at the age of eighteen, we find him first at Bonn, 

 and then at Erlangen, where he graduated, and 

 in 1822 he published his first chemical work. 



It is interesting to observe a mind like Lie- 

 big's in its scientific-swaddling clothes. In Biich- 

 ner's Repertorium fur die Pharmazie, vol. xii., 

 may be found " Some Remarks on the Prepara- 

 tion and Composition of Brugnatelli's and How- 

 ard's Fulminating Silver," by Mr. Liebig, chemi- 

 cal student at Darmstadt. Prof. Kastner adds : 

 " These first proofs of the experimental diligence 

 of a young chemist are commended to the read- 

 er's indulgence," etc. Anything written by Lie- 

 big no longer needs introduction nor indulgence, 

 and he wrote even then as he wrote at last, and 

 as a man must write if he wants to state facts 

 without flourishes. He says, "I have prepared 

 large quantities of fulminating silver according to 

 this prescription during two years, and it has 



never once failed." Then follows a concise and 

 telling criticism of the older methods, and a de- 

 scription of his own, in which the acute observa- 

 tion, the clearness and simplicity, by which Lie- 

 big was afterward distinguished, are conspicuous, 

 and compare favorably with the appendix by 

 which Kastner thought to add weight to the trea- 

 tise. 



A year later we find Liebig at Paris, first in 

 the laboratory of Thenard, then with Gay-Lussac. 

 While at Erlangen he saw that he must complete 

 his studies at Paris, and received a traveling sti- 

 pend from the Graud-duke of Darmstadt for the 

 purpose. 



Thenard, a Frenchman, was the author of the 

 best text and handbook of theoretical and practi- 

 cal chemistry at that time. The most interesting 

 and important researches were then being carried 

 on in France by him and Gay-Lussac, especially in 

 organic chemistry, in which direction young Lie- 

 big's tastes lay. Gay-Lussac had the spirit of a 

 pioneer, and was equally familiar with chemistry 

 and physics. It was he who first discovered the 

 nature of prussic acid, recognized cyanogen as a 

 radical composed of carbon and nitrogen, but 

 which, in combination, plays the same part as the 

 simple elements chlorine, bromine, or iodine ; he 



