very characteristic of him, but unfortunately he has gone on a wrong assumption.

He has evidently been a man of great quickness, at the same time apparently of haste; he has enunciated the most beautiful truths, and left them untouched for worthless speculations, which seemed to need more ingenuity, almost leaving us to doubt how far he understood his own writings. We must, however, give him the honour of understanding what he wrote, smaller honour we can give no man. Still it is perfectly clear that if his theory were as fully developed in his mind as we with our superior opportunity can now see to be deducible from his words, men would have understood him, and the process would have been continued, but neither did he make any advance, nor did he teach others clearly, although the young Berzelius was much excited to curiosity.

It certainly is difficult to tell how discoveries grow, often impossible to tell who is the discoverer; but this we may consider a fair rule, not always easily applied, it is to be confessed, that he is a discoverer who sees distinctly the full bearing of his discoveries; when this does not happen there is a difficulty in giving that man the place due to him. It is clear that Richter, like some others already mentioned, had fundamental principles which would have led him to the atomic theory; but he has evidently been led by foregone conclusions, and the law of planetary distances has been floating in his mind and misleading him, when seeking for the differences in the combining weights of bodies.

The discovery of reciprocating proportion was a very important and memorable one, although the scientific world did not recognise it, another among the many proofs that scientific men are subject to the same bigotted attachment to the laws they have learned, as that class of men hitherto most blamed for bigotry, nor is there any bigotry more engrossing than that which appears to the possessors to be upheld by experimental proof. Who discovered this important fact, it is still

left unascertained: as the expression of a law it is Richter's, but as a fact regarding neutral salts the author appears not to be known.

Among the many disputes on this point it is rather surprising that people should speak without reading the authors they discuss. The supporters of Wenzel have not read him, the supporters of Richter have overlooked his own writings and his own confession, as it appears to me in the preface. But as I give the words every one may judge for himself.

In proceeding with his inquiry one cannot but admire the energy and activity of Richter's mind, and his enthusiastic desire to prove the beauty of the arrangement of creation; it is clear that he lost his way, and spent the greatest part of his energy on a subject which could not with his data lead to great results, and which even now gives us no help, and which was not the next step wanted in chemistry. The science was straining after definite laws, it had none; Richter, with his one great law, might have done wonders, had he only seen its value; he might have found on examination that it was, properly speaking, an inference from another much more general law, and would have then expressed himself in universal terms. But Higgins had expressed himself much more clearly as to combination before him, as already shewn, and only failed because he had not seen it to be general law.

Richter attempted to give the proportion of the acids to bases as an expression of affinity, but this had been already attempted by Kirwan, and was shewn to be unsuccessful.

As a general summary of Richter's most important work, we may say, he found that there was a certain quantitative relation between all bodies, and he made out the laws so far, that when he knew the quantitative analysis of a salt, he could tell its quantitative decomposition with another, but he never saw it with sufficient clearness to be able to express the combining quantities each by its own distinct number,

nor does he appear to have ever proceeded far enough to be able to assign a cause for the phenomenon, or to connect it with any fundamental idea.

He was the founder of the systematic study of stœchiometry, he was an illustrator of one of its important laws, and a defender of regularity in nature. His scientific life was laborious, his love of science sincere, and in all respects he seems to have been a man of high character. After reading his works, and coming occasionally on a sentence which makes us for the moment believe that he has discovered a greater law than we can give to him, and finding that during his whole life he was just on the point of the present atomic laws, one feels that he was perhaps the only man that deserved to discover them, having given himself up entirely to that purpose. It is with regret, therefore, that I leave him also, another combatant who died before the victory.

It has been said that Dalton had read Richter, and had never acknowledged his claims. It is a melancholy thing to see men of talent and learning so readily distrusting their own class, as if dishonesty were so common. I might say the same of Richter, that for more than ten years he continued to publish on stoechiometry, and never once mentioned Higgins, but his whole works shew that he did not see Higgins's writings, or he would have probably got less involved than he did. We learn from Dr. Henry that Dalton had seen Richter's results on reciprocal proportion,* and had received assistance from them, but although they may have assisted him in proving his laws, Richter could never have given him

* Dr. Thomson had said the contrary; but let us take Dr. Henry's information, as being an intimate friend. Dalton could not have seen Richter's whole works, but probably an account of them. They are scarce in England. It cost me a good deal of trouble to get one, even in Germany. The British Museum does not possess a complete copy. Dalton certainly had not read Higgins; and although Dr. William Henry had a copy, we may conclude from his son's work that he had not seen in it the Atomic Theory, as he seems not to have thought it necessary to mention its existence to Dalton.

fundamental ideas. These are much wanted in Richter's chemistry. Richter's cotemporaries did not obtain the atomic theory, although some were students of his work. Berzelius himself did not obtain the atomic theory from Richter, although the most illustrious of the students of Richter's books. Dalton then could not have obtained it, and the direction he takes is perfectly different, the road he went quite clear, and the result he came to entirely distinct from that aimed at by Richter.

In such early days it required a mind of a high order to see as Richter did into the great necessity of permanent laws, and the great structure he raised to make the inquiry shews us that he saw its importance. Had chemists been accustomed to study the works of their own class, such books as his would have rapidly produced results, but the history of the matter speaks ill for the apathy of the men of even that period, and well for his untiring energy and devotion.

CHAPTER X.

FISCHER, BERTHOLLET, PROUST, &c.

WHEN Richter had illustrated the action of neutral salts, and had seen somewhat dimly reciprocal proportion, Fischer (Ernst Gottfried) saw it in a much clearer light, and put it in a more practical form. He took Richter's analyses, and shewed that a constant quantity of one base would unite to a constant quantity of an acid, and that the numbers in all would be reciprocal. Such, one would call the true discovery of reciprocal proportion, were it not, that in this case, the intellectual labour required does not seem great.

It is explained so; "When any substance is taken from one of the two columns, ex. gr., potash from the first column, where the number 1605 stands, then every number of the second column shews how much of that substance is needed to neutralize 1605 of potash." The same thing may be said

* Schweigger's Stachiometrische Reihen. Page 45.