Higgins wrote on phlogiston, his chief object being connected with it. In an octavo volume of above 300 pages these are nearly all the extracts relating to this subject. We find, then, that he did not establish a law in connection with these ideas. We must conclude, then, that he did not see their importance, that he did not see their application. Not only so, but being lost amongst so much material, we do not find that they were so written as to draw any attention, nor does he seem to have wished to do so. He wished to draw attention to what was in reality of less importance, his objections to phlogiston. The magic sword that would have slain all his enemies he threw away as some common truncheon. The magic lamp that would have given brilliance to him and to science, was found, after some years, rotting in his cellar. As regards the effect his book had on his cotemporaries, Dr. Thomson, of Glasgow, is the best authority. We see from him that no idea of an atomic theory was got from Higgins. His opinions were given and received as a speculation more than as expressing a fact or a law.

He says in his Annals of Philosophy, May, 1814, Vol. III., p. 331, "I have certainly affirmed that the atomic theory was not established in Mr. Higgins's book. And here is my reason. I have had that book in my possession since the year 1798, and had perused it carefully; yet I did not find anything in it which had suggested to me the atomic theory. That a small hint would have been sufficient I think pretty clear from this, that I was forcibly struck with Mr. Dalton's statements in 1804, though it did not fill half an octavo page; so much so, indeed, that I afterwards published an account of it; and I still consider myself as the first person who gave the world an outline of the Daltonian theory."

This is put too strongly. Had Dr. Thomson paid as much attention to Higgins's book as to the remarks of Dalton, he would certainly have made a great advance on

the chemists of the period, by understanding definite proportion, and learning to reason in the spirit of the atomic theory.

William Higgins made an advance on Bryan Higgins in this theory of sulphur and heat, and he was a man evidently of an acute mind. But he was destined to find Emerson's saying true, that we often find in the sayings of great men our own rejected ideas. He was heir to the common opinion that atoms existed, and the opinion of Dr. Higgins that they united and formed molecules of compound bodies. He applied the reasoning further, and said that they must then unite in numbers of one or two, or three, and that there could be no intermediate combination, as there were no intermediate division of atoms. He applied this reason in two or three cases. These cases, such as nitric acid, are so clear and beautiful, that we can only be surprised that the general law was not seized on. They are the first clear and satisfactory reasons given for saturation, and for definite proportion in general. Higgins was therefore the first man who used the idea of atoms with such force as to be serviceable in chemistry. He used the idea of ultimate particles and the molecular state of bodies to illustrate saturation, and definite and multiple proportion, and gave us therefore the fundamental ideas of stoechiometry as they exists in chemical science, from which everything else might have easily flowed.

He had seen the right road, but dared not go farther. But we must take his own apology, "Est quoddam prodire tenus, si non datur ultra." It is something to have gone thus far, if he had no power to go beyond it.

Like Dr. Higgins, and the most of the chemists of last century, he assumed certain forces of attraction, and endeavoured to give comparative values to the forces of combination. These numbers representing affinity misled Higgins. Had he seen any general law, he would have seen that weights repre

sented the comparative number of his atoms, but this he did not see with any distinctness, or he would have used Kirwan's numbers, which he knew well enough, and would have found in them atomic weights. But atomic weights were never thought of at all. It was not even certain then that all matters gravitated, although he held the present opinions on it. He reasoned to a certain extent in the true spirit of the atomic theory, but becoming entirely involved in dynamics, he entirely missed his way. Dynamics have hitherto entirely failed in chemistry. Their power has been used in upsetting their friends, and Higgins fell a victim to their forces.

Having for a moment laid hold of the idea that bodies which are atomically constituted must be formed of the union of one or more bodies, and of no intermediate atoms, he drew insufficient conclusions, and all its prospective advantages were lost to him. The want of suitable results, which it was his fault for not finding, seems to have caused him to let go his magic weapon, or to view his own opinion as a speculation. In his mind they exist as very little more.

I look upon him as the first man who ever in his imagination formed a correct atomic compound, and gave a correct analysis, in spite of the thousands of previous speculations and the simplicity of the idea, but one who lost the opportunity of elevating his idea into a great law of nature. It is well to express the claim of a discoverer in the widest and in the fewest words. He expressed the fact of atomic simple and multiple proportion, which is the foundation for all the other atomic laws, although in his mind it was not raised to the dignity of a great law, and it is for great laws only that we can give great honours in this case.

Higgins speaks so clearly and simply that we can readily believe that he would have illustrated the laws of chemical combination with great beauty had he seen the great value of his ideas. There is no obscurity in his language; there is no

difficulty in telling exactly his place in science; but there is a difficulty in defining it exactly when we have to deal with Dalton, who grasped the whole so much more firmly, enlarged it, placed it, and established it in a series of laws. Any one to be put before Higgins must have made great advances: he cannot be put down by any obscure sentences dragged from any author. Any one to eclipse him must be fuller, more decisive, and more systematic.

From the want of these qualities Higgins appears more in the character of a great thinker than of a great discoverer.

CHAPTER IX.

RICHTER.

DURING the disputes as to Dalton's priority of discovery, it was frequently asserted that his atomic laws were not new, and they were, as is usual in such cases, attributed to various persons. Of these persons, Higgins, in this country, and Richter, in Germany, have been the most prominent. I have endeavoured to show exactly the position of Higgins; I shall do the same with Richter. Higgins came first with clearness and simplicity, uttering a beautiful idea which he failed to follow up; Richter came close after him, with great labour and enthusiasm, filled with a great idea of the study in which he was engaged, and obtained a law which he failed to follow up; he lost himself in complicated theories, having no idea how simple was the truth he sought for. Both were neglected, as happens when men fail to give completeness to their inquiries, even in the eyes of those who study and are willing to learn.

Richter's books are" Anfangsgründe der Stoechyometrie oder Messkunst Chymischer Elemente." 3 vols. Bresslau und Hirschberg, 1792-4; and "Ueber die Neuern Gegenstände der Chymie," 1791-1802.

I shall give rather copious extracts from his works, shewing the direction of his inquiries, and the ends he attained.

RICHTER, VOL. I., PREFACE.

"Mathematics includes all those sciences which refer to magnitude, and consequently a science lies more or less in the province of mathematics (geometry), according as it requires the determination of magnitudes. In chemical experiments