patients. But that is only one aspect of the matter. There is also prevention to be considered; and that is a bigger problem still, for the reason already stated, viz. the very nature of the sexual instincts. Whatever measures are adopted with a view to enlightenment, the process must necessarily be slow. Even full knowledge as to consequences cannot master the passions; and it is impossible to have half the population looking after the other half. Most would-be reformers, however good their intentions, know very little really about the matter and require to be educated. Before drastic measures are taken, it will be necessary to study the subject carefully from the social as well as the medical point of view, to think out ways and means, and to apply the gravest consideration in forecasting the consequences. Otherwise we shall only repeat the errors of the past, and run the risk of much tribulation for no reward.

If, as would be inevitable in case of compulsory notification, medical treatment is to be adopted on a large scale, communities must be prepared to spend large sums. The treatment of syphilis is a prolonged one; and, if salvarsan is to be used, the expense would be largely increased, for it is not a cheap preparation. If microscopical and blood examinations are to be generally made, special departments and wards and a large staff of medical men and pathologists with laboratories will be required and will have to be paid for; and the cost would be very great.

Ardent suffragists appear to expect immense results from the grant of the franchise to women. They do not explain how these results are to be obtained. Measures which may suit one country may fail when applied to another; the particular genius of a nation must be borne in mind. Moreover, the peculiar portability of the disease and the increasingly large and rapid movements of population have to be taken into account. It is one thing to apply remedies to a sparsely populated area, and quite another to handle a vast city like London, which is the clearing-house of humanity, with representatives of all parts of the globe streaming in and out. If the parliamentary action of women reformers could improve the condition of things in their own country-which is, to say the least, very

doubtful-fresh infection would constantly be coming in from abroad. Syphilis is common all over the world. One may establish a cordon sanitaire and quarantine for cholera and plague, but it would be impossible to do this for venereal diseases. This makes the stamping out of syphilis a practical impossibility. It is well to realise what one cannot do, and leave it alone; and a reasoned masterly inactivity may in some cases answer better in the long run than impulsive meddlesome interference.

In conclusion, there is no doubt syphilis is widespread and deep-seated. This is well-known to those who are actually dealing with the disease in its various and elusive aspects. The very nature of the syphilitic infection, as will be readily gathered from what we have said, makes any figures which might be adduced very fallacious. For that reason we have not dealt with the statistical aspect of the question. Many cases do not come under medical observation at all, others are not detected; and the part played by syphilis as a factor in obscure conditions is frequently unrecognised, especially in death certification.

That a gradual and in the end considerable amelioration may be achieved we are entitled to hope, although the prospect of altogether eradicating syphilis is remote indeed. But such improvement as is possible will be the result, not of what are called heroic and are really rash and violent measures, but of the gradual spread of public spirit, of the sense of duty, and of the strengthening of self-control. These are no doubt counsels of perfection, but some tangible results may perhaps be expected if the public can be made to realise what syphilis really means.*

GEORGE PERNET.

Since this article was in type, Mrs Creighton has published an admirable little work entitled 'The Social Disease and how to fight it' (Longmans). While paying particular attention to the attitude which women should adopt towards the question, the book is full of sound judgment and wise advice which the general public will do well to accept.

Art. 8.-SIR DAVID GILL AND RECENT ASTRONOMY.

A History and Description of the Royal Observatory, Cape of Good Hope. By Sir David Gill, K.C.B. London: H.M. Stationery Office, 1913.

IN the autumn of 1913, shortly before the death of Sir David Gill, his book, called 'A History and Description of the Royal Observatory, Cape of Good Hope,' was published by order of the Lords Commissioners of the Admiralty in obedience to His Majesty's command. It is a large quarto, of which 136 pp. give, with many excellent plates, a description of the splendid instruments designed for and erected at the Cape under the supervision of Sir David Gill, who, from 1879 to 1907, held the post of H.M. Astronomer there. The introductory history, extending to 190 pages, records the work done at the Observatory, both before and after his appointment.

The value of this book to astronomers, professional or amateur, is incalculable. The death of the author on January 24, 1914, so soon after he had thus summarised a life's work in those pages, ensures the interest of a large outside public in the extraordinary developments made in the science of astronomy during his lifetime. It also justifies the reviewer in glancing a little beyond the written pages to speak of the beautiful mind and the inspiring ideals of this great man, who will live in the hearts of all who knew him, not only as among the greatest of astronomers, but also as one of the noblest and most lovable of men.

During the two centuries that followed the publication of Sir Isaac Newton's 'Principia,' the greatest delight of astronomers was to watch the members of the solar system, to measure their positions with the highest precision, to learn to foretell their movements, and to test the universality of the law of gravitation in every case of apparent deviation from that law. The discovery of Neptune in 1846, before it had ever been seen, by its disturbing action upon the planet Uranus, was the crowning triumph of that phase of astronomical research. After this, attention came to be directed more and more to the so-called fixed stars. The revolutions, in many cases, of a pair of stars round a common centre of

gravity, exactly as in the solar system, seemed to extend the law of gravitation to stellar systems. Even the variability in the brightness of some stars could be attributed to the mutual eclipses of two stars, visible only as one, while revolving round each other; and the spectroscope added new evidence of the existence of such stellar systems subject to the force of gravitation. Then the direction and amount of the minute proper motions of some stars were measured, and, after their distances had been, with great difficulty, found in some cases, the actual velocity indicated by the proper motion could be expressed in miles per second. Gradually data accumulated for building up a stellar universe in perspective, and detecting the motion of our sun among the stars, and discovering the existence of great swarms of stars, the members of each swarm all moving in the same direction.

In later years the invention of the spectroscope has helped to divert attention from the solar to the stellar systems. This instrument enables the constitution of the stars to be discovered by the colours of the light emitted. The appearance of the spectrum as a ribbon of colours from red to violet along its length is too well known to need description; also the absence of certain colours, as indicated by black lines crossing the ribbon. The spectrum of the star Arcturus has hundreds of these black lines corresponding in position exactly with the lines shown in the spectroscope by glowing iron vapour, because iron is present in the star Arcturus. So with other chemical elements and with other stars. This study has originated the new astronomy dealing with the physical constitution of all the heavenly bodies.

But the spectroscope has another wonderful application. Sometimes the black lines representing iron in the spectrum of a star like Arcturus are shifted slightly to one side or other of the corresponding lines in the spectrum of glowing iron vapour; and this, when interpreted by a knowledge of the theory of light, enables astronomers to say whether the distance from us to any star is increasing or diminishing, and to measure the speed in miles per second. This marvellous faculty has given a new impetus to the study of stellar motions, and to the detection of stellar systems and stellar swarms.

The transition from the old to the new astronomy, from the period of precision in determining the positions of the heavenly bodies to the period of studying them with the spectroscope and applying photography, coincides with the period of Sir David Gill's activities in the world of science. That fact gives an enhanced value to the book under review and to the life of its author. The Description' takes a position such as Tycho Brahe's description of the Uranienburg Observatory, or Wilhelm Struve's of the Pulkova Observatory, held in their days; and for long it will be used as a guide to the design and construction of astronomical instruments of precision. The chief value of the History' for astronomers throughout the world is that it contains a condensed summary of the work of its author. Before Gill took up his duties in South Africa, Fallowes, Henderson, Maclear and Stone, with their assistants, had done the best they could as H.M. Astronomers at the Cape Observatory, controlled as it was by the Admiralty of an economising, and not too sympathetic Government; and the result was pitiable as the outcome of the premier Observatory of the southern hemisphere. From the moment when David Gill, the man of energy who always knew exactly what he wanted to accomplish, appeared upon the scene, this Observatory developed with giant strides, and became, before he left it, a model for all the world, fitted with the finest instruments of precision, and furnished with a devoted staff adding yearly to the published results which enriched astronomy, under the direction of their honoured chief.

David Gill, son of David Gill, J.P., of Blairythan, Aberdeenshire, was born on June 12, 1843. He became a student at Marischal College and University, Aberdeen. Thus he came under the genial influence of that lovable, unselfish and profound philosopher at Marischal College, Professor James Clerk Maxwell. He was one of the few to gain the full benefit from the lectures, for Maxwell (like Kelvin) was a failure in teaching the average young men in his class. After each lecture, he would carry on his instruction by conversation with his favourite pupils, and no one was more receptive than young Gill, At the age of twenty he went to Edinburgh