MODERN CHEMISTRY. 459 



but a slight idea of the magnitude and variety of these 

 researches. Scarcely have we even named the great class of 

 vegetable alkaloids obtained by modern analysis; many of 

 them most singular in their action, medicinally or as poisons, 

 on the animal economy. Of the acids, at least 300 in 

 number, which are described in this department of chemistry, 

 we have spoken almost as cursorily. Arranged in different 

 series, upon some predominant character of each (the alco- 

 holic, aromatic, fatty series, &c.), these organic acids strik- 

 ingly illustrate the doctrine of definite proportions in its 

 every part. In the fatty series for example, including more 

 than twenty members, the oxygen is the same in all ; the 

 other constituents, carbon and hydrogen, preserving the 

 same exact ratio of increase throughout the whole of the 

 scale. Gaps, determined by the very exactness of this ratio, 

 have been left here as in the other series. One by one the 

 progress of discovery is filling them up ; and under numeri- 

 cal conditions precisely those which the theory requires. 



In every part of this picture of modern Chemistry it will 

 be seen how wonderfully the objects cohere together; and 

 amidst the immense multiplication of facts, and even of new 

 classes of phenomena, how strikingly all converge around 

 the law of definite proportions in combination the key- 

 stone of Chemistry, and the index to all the actions involved 

 in it. The name of Liebig, as we have seen, is ever promi- 

 nent in this narrative. If there were license for comparison 

 in things so different, we should be tempted to call him the 

 Rubens of the chemical school, from the power he possesses 

 of boldly grouping together his results, and enforcing con- 

 clusions which have escaped more timid reasoners. Yet 

 while thus successful in reaching great truths felicissime 

 audax we are bound to admit a certain rashness which 

 now and then hurries him into inferences not tenable under 



