a decided stand in regard to the question of solar heat. He rejects the theories of Helmholtz and Kelvin, as being incompatible with geological evidence. While chemical theories have been considered hopelessly insufficient to account for the tremendous outpour of heat observed, Arrhenius advocates a return to them. He points out that the exchanges of energy in t lie redistribution of chemical equilibria are enormously greater at very high temperatures than at lower ones and that for this reason computations made from laboratory data have no bearing on the problem. While this hypothesis of Arrhenius may not stand the test of time, it is an interesting one and especially in view of the peculiar heat effects manifested by radium. Of the book itself Professor Barus says, in a review: "As a whole the work will take rank beside the great contributions of Mohn, Guldberg (who, it will be noted, shared with Arrhenius this double allegiance to chemistry and geophysics), and others, who have made meteorology a debtor to the thinkers of the North." It may also be mentioned that Arrhenius will attend the International Congress of Arts and Science at St. Louis as one of the speakers before the Section of the Sciences of the Earth.
The most recent papers of Arrhenius deal with the chemistry of serums, and it seems probable that the study of medical problems will occupy much of his time during the next few years. In Arrhenius w r e have a man who has received the Nobel prize before he was forty-five, and whose scientific work ranges from, salt solutions to comets and from glacial periods to the typhoid bacillus. Such a record lends little support to the belief that a scientific man must be a narrow specialist if he is to attain eminence. This belief rests on a misapprehension. It is true that scientific men are accumulating facts at a tremendous rate and that this apparently makes it more and more difficult for any one man to be master of anything more than a small branch of a single science. Along with this accumulation of isolated facts, however, there comes the development of great simplifying generalizations or laws which enable men to grasp and remember an enormous number of facts. It is only during the brief periods when the discovery of new facts has not yet given rise to newer and more comprehensive theories that there is even an appearance of narrowness.
Carolus Linnæus was born on May 13, 1707, and suggestions have already been made as to the celebration of the bicentenary of his birth. The centenary of his death was duly commemorated by the erection of a statue in Stockholm by Professor Kjelberg which stands in the Humlegarden, and represents the great naturalist holding in his hand the 'Systema Naturæ' and surrounded by allegorical figures representing botany, zoology, mineralogy and medicine. Just what form the celebration of the bicentenary of Linnaeus's birth will take in his native country has not been decided, but it is not perhaps too early to make preparations for a suitable commemoration in America.
There has perhaps been in recent years a tendency to depreciate the work of Linnaeus, some of his ideas having been discovered in the publications of previous writers and his works naturally containing many mistakes. But he is the founder of botany and in a way of modern natural history to an extent but rarely vouchsafed in science to a single man. He left order where there had been confusion, and largely prescribed the development of a science for a century, until the time of Darwin and the theory of evolution. Linnaeus himself seems almost to have foreseen the course of events, for he said: 'A natural method is the first and last thing to be desired in botany; nature does not make leaps.'