These papers are now collected at the request of friends and correspondents, who think that they may be useful; and two new essays are added. Most of the articles were written as occasion called for them within the past sixteen years, and contributed to various periodicals, with little thought of their forming a series, and none of ever bringing them together into a volume, although one of them (the... more...

IN the last Lecture I endeavoured to prove to you that, while, as a general rule, organic beings tend to reproduce their kind, there is in them, also, a constantly recurring tendency to vary—to vary to a greater or to a less extent. Such a variety, I pointed out to you, might arise from causes which we do not understand; we therefore called it spontaneous; and it might come into existence as a... more...

WHAT IS EUGENICS? The wisest thing in the world is to cry out before you are hurt. It is no good to cry out after you are hurt; especially after you are mortally hurt. People talk about the impatience of the populace; but sound historians know that most tyrannies have been possible because men moved too late. It is often essential to resist a tyranny before it exists. It is no answer to say, with a... more...

Chapter I.—General Remarks. This volume is the first instalment of a work that admits of wide extension. Its object is to serve as an index to the achievements of those families which, having been exceptionally productive of noteworthy persons, seem especially suitable for biographical investigation. The facts that are given here are avowedly bald and imperfect; nevertheless, they lead to certain... more...

CHAPTER I. STRUCTURE OF THE BACTERIA AND CONDITIONS GOVERNING THEIR DEVELOPMENT AND DISTRIBUTION. Before one can gain any intelligent conception of the manner in which bacteria affect dairying, it is first necessary to know something of the life history of these organisms in general, how they live, move and react toward their environment. Nature of Bacteria. Toadstools, smuts, rusts and mildews are... more...

The study of the History of Chemistry as an art, or as a science, is one which possesses peculiar fascination for its votaries. It has been the subject of deep research and much discussion, much has been written upon the subject, and many theories have been broached to account for its origin. We have had laid before us by Professor Ferguson, in his papers on this subject of Chemical History, very... more...

I THREE PERIODS OF PROGRESS The story of Robinson Crusoe is an allegory of human history. Man is a castaway upon a desert planet, isolated from other inhabited worlds—if there be any such—by millions of miles of untraversable space. He is absolutely dependent upon his own exertions, for this world of his, as Wells says, has no imports except meteorites and no exports of any kind. Man has no wrecked... more...

The very high character of Mr Lavoisier as a chemical philosopher, and the great revolution which, in the opinion of many excellent chemists, he has effected in the theory of chemistry, has long made it much desired to have a connected account of his discoveries, and of the new theory he has founded upon the modern experiments written by himself. This is now accomplished by the publication of his... more...

THE PREFACE. One reason for the present publication has been the favourable reception of those of my Observations on different kinds of air, which were published in the Philosophical Transactions for the year 1772, and the demand for them by persons who did not chuse, for the sake of those papers only, to purchase the whole volume in which they were contained. Another motive was the additions to my... more...

Hoffman, in one of his observations, gives the history of a powder called magnesia alba, which had long been used and esteemed as a mild and tasteless purgative; but the method of preparing it was not generally known before he made it public. It was originally obtained from a liquor called the mother of nitre, which is produced in the following manner: Salt-petre is separated from the brine which first... more...