32 



KNOWLEDGE 



[February 1, 1896. 



focal length. The outcome may seem small for so great 

 an expenditure of pains, but those two hundred failures 

 made the octagon chapel organist an expert. Dut the 

 most interesting chapter is that one which deals with 

 "The InllucnceofllerschersCareer on Modern Astronomy." 

 Of Sir .lohn llerschel there is a chronological table of 

 successes. " His life was a tissue of felicities. l''or him there 

 was no we;irv waiting, uo heart-sickening disappointment, 

 no vicissitudes of fortune, no mental or moral tempests." 

 He was a physicist, poet, chemist, mathematician ; he was 

 also an astronomer. There is never need to dilate on Sir 

 William Herschel's genius ; the fact is self-evident. Miss 

 Clorke insists again and again that Sir .John was a great 

 man ; that he stood " supremely at the head of the list " ; 

 that he was a successful man. The impression remains 

 that it was his very success that was a failure ; that 

 if the hill of pre-eminence is smooth, it offers small grip to 

 the foot of the climber. Sir .lohn worshipped many gods : 

 his father, but one. 



'J'lifCill: Ihttlincs of (icnenil Andtomy itml I'ln/siiiloi/i/. 

 By Dr. Oscar Hertwig. Translated by M. Campbell, and 

 edited by Dr. H. .T. Campbell. (Swan Sonnenschein.) 

 Illustrated. 12s. "Thecell theory," remarks Prof. Hertwig, 

 " is the centre around which the biological research of the 

 present time revolves." The theory that organisms are 

 composed of cells was first suggested by the study of plant- 

 structure, and the term " cell " was applied to the small 

 room-like spaces, provided with firm walls and tilled with 

 fiuid, to be seen in plants. Both Schleiden and Schwann 

 (183S) believed the cell to be a small vesicle, with a firm 

 membrane enclosing fluid contents ; but, later, Max 

 Schultze (1H60) defined it as a small mass of protoplasm 

 endowed with the attributes of life. Improved means and 

 methods of observation have shown that this conception 

 must give way to a better, and the definition now held is 

 that the cell is a little mass of protoplasm, which contains 

 in its interior a specially-formed portion, the nucleus. It 

 is around this nucleus that biological investigations are 

 now mostly centred ; its nature, functions, changes, and 

 potentialities will form the subject of work and discussion 

 for many years to come. In fact, upon the nucleus is now 

 concentrated the attention that in earlier days was given 

 to the cell. The cell is very uniform in appearance 

 throughout the animal and vegetable kingdom, and contains 

 the key to many problems of life, while its relations to the 

 protoplasm in which it is embedded are of absorbing 

 interest. Prof. Hertwig is recognized as one of the greatest 

 authorities on cell-structure, and this accurate translation 

 of his treatise on the subject will bo heartily welcomed by 

 those who do not read German fluently, and yet desire to 

 learn what is known about the "ultimate particles" of life. 

 The historical course of the development of the more impor- 

 tant theories relating to the cell is traced, and the knowledge 

 gained by means of microscopical, chemico-physical, and 

 other methods of inquiry is clearly set down. Few works 

 are more valuable to students of histology than this, 

 and in none will a better account be found of the nature 

 and attributes of the cell-organism — that little universe 

 the mysteries of which are slowly being unravelled. Prof. 

 Hertwig is happy in having such an excellent translator 

 and careful editor as those to whom the English version of 

 his work has been entrusted. 



Uritish Fuwius-Flora. By George ^lassee. Vol. IV. 

 (George Bell .V; Sons.) 7s. 6d. This is the fourth 

 volume of a standard text-book of mycology, written by a 

 recognized authority on the subject. In it the species 

 of fungi included in those families of the large natural 

 order of the Ascomycetes are classified and described. 

 Acting on his opinion that " no one can be considered to 



know a species thoroughly until it has been worked out by 

 himself," Mr. Massee has personally examined type speci- 

 mens in all cases where they were accessible (his position 

 at Kew giving him exceptional opportunities for doing so), 

 and has thus been able to make his descriptions of the 

 characters of species full and trustworthy. 



Siwplf Mcthtih for Ih'lertirKj Food Adulteration. By 

 John A. P.ower. (London : S.P.C.K.) Mr. John Bower 

 chooses as his text the well-known words of Tyndall : 

 " Apply the principles of science, and make them available 

 to the needs, the comforts, and luxuries of life." This he 

 has very indifferently succeeded in doing in the present 

 volume, which is full of the most glaring errors, and gives 

 such trivial tests lor adulteration that those who endeavour 

 to follow them will find that their efforts are thrown away. 

 When we mention that we find such slovenly expressions 

 as " the precipitation of the lime " on boiling hard water, 

 that silver nitrate gives a white precipitate with the 

 "organic impurities" in water, and that a "serviceable 

 filter " can be made out of a llower-pot and some sand and 

 magnetic oxide of iron, our readers will see that this 

 adverse criticism is well deserved. 



The Scientific Foundations of Anahjtical Chemistry. By 

 W. Ostwald. Translated by G. McGowan. (Macmillan.) 

 Prof. Ostwald's work during the last ten years on the 

 borderland of chemistry and physics has naturally led 

 him to look upon routine analytical work in the laboratory 

 as almost devoid of any scientific basis. And in this 

 respect we are fully in agreement with him. In scarcely 

 any of the text-books do we find any mention of theory, 

 and in the majority of examinations the practical work can 

 be passed by a clever student who crams up a set of 

 analytical tables. No student could pass a practical 

 examination by reading Prof. Ostwald's book, but any one 

 who has read it carefully through, and proved the different 

 reactions in the laboratory, would have a real knowledge 

 of practical chemistry. To the older student the work 

 appeals, as it throws new light on many reactions which 

 seem at first sight to be unique and uninfluenced by any 

 general laws. We hope that all teachers will endeavour 

 to frame their instruction on the lines laid down by the 

 author, so that practical chemistry may cease to be simply 

 the art of test tubing. 



Text-Booh- of tlie Emhryoloii}/ of Inrertehrates. By Dr. 

 E. Korschelt and Dr. K. Heider, Translated from the 

 German by Dr. E. L. Mark and Dr. W. Mc M. Wood- 

 worth. Part I. (Swan Sonnenschein.) Illustrated. 1.5s. 

 Students of animal morphology well know the great value 

 of the Lehrhuch of which this is a translation. To be 

 able to read the work in English will, however, be a boon 

 to many zoologists who find the perusal of the German 

 text a rather laborious task. And even to those who have 

 no difficulty in reading the original work the translation 

 will be valuable, for numerous additions, recounting the 

 most important results arrived at by embryologists since 

 the date of first publication, have been made by Drs. 

 Korschelt and Heider, and appear for the first time in the 

 present edition. The complete work is published in three 

 parts, and the first of these deals with the Porifera, 

 Cnidaria, Ctenophora, Vermes, Enteropneusta,and Echino- 

 dermata. It is the translation of this part that is now 

 before us, and we are glad to notice that translations of 

 Parts II. and III. are in prepr^ration. German men of 

 science have a wonderful faculty for collecting knowledge, 

 and the present volume is a good example of what they 

 can do in that way. Practically all the literature of com- 

 parative embryology appears to have been consulted in the 

 preparation of the work, and both students and special 



