July 1 8. 1S89] 



NATURE 



-/ 



Ting within fifteen months in the practice of a phthisical 

 midwife, who was in the habit of sucking the mucous 

 from the mouths of the new-born infants, and of blowing 

 air into their lungs. Pigs fed upon the milk of tuberculous 

 cows became tubercular in five weeks. 



{c) By inhalation. Animals after a few inhalations of 

 tubercular sputum, disseminated in a spray, readily became 

 infected. Koch holds that no other substances than 

 tubercular products when introduced into an animal will 

 produce tuberculosis. 



The resume of the changes which take place in the 

 blood in various diseases is most complete and up to date. 

 The latter part of the book deals with the diseases of the 

 circulatory organs. 



Among alterations which are desirable in a new edition 

 we would suggest that the forms for \}s\^ post-mortem re- 

 ports which occupy four pages should be omitted ; or, if not, 

 they should be made much more complete. Many important 

 headings, such as lymphatic glands, joints, prostate, &c., 

 are wanting. Fig. 25 is an unfortunate illustration of lar- 

 daceous disease of the liver in which the liver cells are 

 affected, and should be replaced by a more typical case 

 with healthy cells. We would demur to the statements 

 that lymphadenoma produces great anaemia and infil- 

 trates tissues — that is, in the sense in which sarcoma 

 is said to infiltrate. The growths extend only along 

 lymph-channels, and do not infiltrate outside these. On 

 p. 82, sulphide of potassium should be sulphite. 



We congratulate the author on the general excellence 

 arid practical nature of his book, and shall await with 

 interest the second volume. The arrangement of the 

 type, the paper, and the illustrations are unexceptionable, 

 and reflect the greatest credit upon all concerned. 



. OUR BOOK SHELF. 



A Graduated Course of Natural Science. Part I. By 

 ' Benjamin Loewy, F.R.A.S. (London : Macmillan and 

 Co., 1889.) 



This is an admirable little book which has been prepared 

 for the use of teachers and students in schools where 

 elementary ideas of physics and chemistry form part of 

 the course of training. It is intended for elementary 

 students only, and it is not too much to say that the 

 various experiments and inferences are well within the 

 scope of every boy and girl of ordinary ability. It is but 

 to be expected that during his twenty years' experience 

 the author has become thoroughly acquainted with the 

 difficulties met with by young students, and with the best 

 methods of overcoming them. 



An experiment is first described, and the inferences to 

 be drawn are then discussed, the simple conversational 

 style being especially suitable for young pupils. The 

 subjects are arranged in a very natural order, and it would 

 be difficult to suggest improvements. Very practical 

 suggestions are made as to the best way of arranging for 

 each student to perform the experiments. A simple 

 board, about 3 feet long by 18 inches wide, temporarily 

 screwed to the top of the desk, has been found sufficient 

 to accommodate two or three pupils, so that it is an easy 

 matter to have thirty or forty working at the same time. 

 To make the book more useful to teachers, a series of 

 questions has been put at the end of each chapter. 



We strongly recommend the book to the notice of 

 teachers likely to be interested in the subjects of which it 

 treats. 



Flora of Switzerland for the use of Tourists and Field- 

 Botanists. By A. Gremli. Translated from the Fifth 

 Edition, by Leonard W. Paitson. (London : David 

 Nutt, 1889.) 



English visitors to Switzerland who happen to be 

 interested in botany must often have regretted that they 

 did not possess a really good hand-book of the Swiss flora. 

 The translator of Herr Gremli's well-known work has 

 provided a volume which will exactly meet their wishes. 

 The original book has been widely circulated in Germany, 

 and its materials are so ample, and so carefully and 

 intelligently arranged, that it well deserves its popularity. 

 In the fifth edition many improvements were made, and 

 these are, of course, embodied in the present rendering. 

 Mr. Paitson has also been able to include the new matter 

 presented in the French translation by M. J. J. Vetter 

 (1885), and corrections and additions published (1887) in 

 the latest — the fourth — of Herr Gremli's supplements. 

 Although the work is intended in the first place for 

 persons beginning the study of botany, it contains much 

 information with regard to new species that will be of 

 service to more advanced botanists. We may note that 

 the English volume is clearly printed, and that it is of a 

 size convenient for the use of tourists. 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents . Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anony^nous covimunications.\ 



Coral Reefs. 



I AM obliged to Mr. Murray and Dr. Guppy for their 

 courteous replies to my questions. Mr. Murray knows how 

 pleasant a duty it is on the part of Admiralty surveyors to 

 collect materials for the investigation of men of science like 

 himself. Perhaps he will allow me to say tliat the theory of 

 wave action spreading out the loose materials of a volcanic 

 island is difficult to understand in view of the fact that islands 

 in the same locality, such for instance as Mokongai and Wakaya 

 in the Fiji Group, have their barriers far away from the land on 

 exactly opposite sides. If he will excuse repetition, I desire 

 again to point to the Exploring Isles, and to the great distance 

 between the barrier and the island of Vanua Mbalavu ; also to 

 the fact that the waves, for all hut a few days in the year, attack 

 the island from a direction varying between south-south-east and 

 east-north-east, principally east-south-east. Although there is 

 much upraised coral at the north end of Vanua Mbalavu, the 

 formation is chiefly volcanic. 



The shallow nature of the Na Solo lagoon is, I presume, due 

 to the detritus from the now sunken island, and the fragments 

 from the reef washed over by the heavy seas at high tide. The 

 bank west of Ono, in the Kandavu Group, is terminated by a 

 sunken barrier, similar to that south of Viv\a and north-west of 

 Mbengha ; and is not a continuous reef awash, because of the 

 muddy streams from Ono sweeping to leeward, and also for the 

 reason, admitted on all sides, that coral does not grow with so 

 much vigour where there is no surf. 



Dr. CJuppy's simile, of an engineer having constructed and 

 afterwards repaired a bridge, is not, in my opinion, a good one. 

 A bridge is a structure accomplished on mathematical principles, 

 good or bad. If good, it will stand ; if bad, it will sooner or 

 later fall. Mr. Darwin's theory, like other theories, is not 

 capable of mathematical proof ; and it is deduced from personal 

 observation only in a very limited degree. The second edition 

 of his work indicates, that after thirty-two years' further experi- 

 ence in weighing, deducing, and generalizing of a similar 

 character in other branches of natural history, and receiving the 

 views of those opposed to his theory on this special subject, he 

 still adheres to his original opinion. The principle of his work 

 was, in all cases, very much the same ; and, considering the 

 labour which he devoted to the first study of the question several 

 years after he returned from his voyage, it is hardly conceivable 

 that the origin and formation of coral reefs did not occupy a 



