1820.] Specific Gravity of Gases. 167 



gas above the truth and the sagacity to determine the true speci- 

 fic gravity without any original experiments of his own; but 

 merely by a close and ingenious comparison of the experiments 

 of others: This is a degree of skill that places its possessor m a 

 more elevated rank than a mere experimenter and "Kl^'^es jne 

 to prognosticate with confidence that if Dr. Prout persevere m 

 the caieer which he has begun with so niuch ardour, .he science 

 of chemistry will be indebted to him for discoveries ot a tai 

 hiaher and more important kind than have hitherto been made. 

 Chemistry, for a long series of years, owed its progress to expe- 

 rimental industry alone. At that time mathematical reasoning 

 could not be applied to it, and the utmost stretch of human saga- 

 city could not prevent the merely speculative chemist from going 

 altogether astray. It was then that activity and industry led to 

 the greatest harvest of discovery, and that Dr. Priestley, without 

 any mathematical knowledge whatever, and without any turn tor 

 complete investigation, contributed more to the improvement of 

 chemistry than Mr. Cavendish himself, the most accurate expe- 

 rimenter, and the most sagacious reasoner that Great Britain 

 has produced, with the sole exception of tMr Isaac ISevvton ; but 

 the introduction of the atomic theory has put the science upon a 

 very different footing. We now begin to have glimpses ot the 

 general laws which nature obeys in the union of elementary 

 bodies. Henceforth the great object ot chemists must be to 

 discover these general laws ; nnd no progress can be made in 

 such investigations without the aid of analytical reasoning, and 

 without a mind trained to mathematical speculations. Chemistry 

 has not advanced far enough to enable us to make a sing e step 

 without the aid of experiment; but neither can we make any 

 proo-ress in it of the least value unless we caU in mathematics to 

 Jur'assistance. Now, therefore, is the period of the science, 

 when such men as Dr. Prout and Mr. Herschel, may be certaia 

 <5f reaping a rich harvest of discovery and renown, it they clioose 

 only to devote to this delightful science the requisite degree ot 

 attention, and combine their experimental skill with tlieir 

 mathematical acquirements. Mere experimenters may rehnquish 

 the field ; for there is not a great deal more which they can do, 

 and to mere mathematicians chemistry at present, and probably 

 for some time to come, is forbidden ground. Indeed to be con- 

 vinced of the little utility of mere mathematical formulas towards 

 promoting this science without the aid of expermient, the reader 

 has only to peruse the chemical part of Biot's Traite de Pliysique, 

 where he will find abundance of specimens of most elaborate 

 mathematical investigations, which leave every subject precisely 

 in the state in which they found it. -a 



Dr. Prout demonstrated from the known composition and 

 specific gravity of ammoni«cal gas that the true specihc gravity 

 of hydrogen gas is U-U694, or exactly ^^\h of that of oxygen 



