NA TURE 



277 



THURSDAY, JUNE i, 1916. 



APPLE-GROWING FOR PROFIT. 



The Apple : a Practical Treatise dealing with the 

 Latest Modern Practices of Apple Culture. By 

 A. E. Wilkinson. Pp. xii + 492. (Boston and 

 London: Ginn and Co., 191 5.) Price 8s. 6d. 



MR. WILKINSON'S monograph is a very 

 good example of a type of book which 

 is indigenous to the New World. Writers of such 

 monographs look at their subject keenly and ex- 

 clusively from its commercial aspect. They collect 

 or recount from their experience every item of 

 information the possession of which by a grower 

 is calculated to make his proposition pay ; with 

 equal ruthlessness they exclude everything a 

 knowledge of which does not appear likely to 

 lead to monetary profit. 



Thus the present work abounds in sound and 

 useful information on every section of commercial 

 apple-growing, yet it neither mentions nor de- 

 scribes any form of training other than that for 

 the production of a " vase"-shaped (open-headed) 

 or pyramidal standard. Espaliers, cordons, and 

 the subtler forms of trained tree beloved of thrifty 

 Frenchmen are ignored completely. The American 

 apple-tree has, in truth, been standardised, and 

 the form prescribed is the low standard. Dwarf- 

 ing stocks are allowed — in the home garden. 

 Similarly, admirable accounts are given of frost 

 prevention by the use of "heaters," of picking, 

 packing, grading, marketing, and advertising, 

 yet the descriptions of the chief varieties of apple 

 are so brief and unclassified that growers would 

 have the greatest difficulty in naming an unknown 

 variety which happened to come into their hands. 

 So long as information has a commercial bear- 

 ing it may, however, be included, even though it 

 lack precision. For example, colour appears to 

 be a very important attribute of American apples, 

 and accordingly the subject is considered with 

 some thoroughness, and quite inconclusive experi- 

 ments are cited, as, for example, those on the in- 

 fluence of manuring with potash salts on the pro- 

 duction of colour. Science is trying hard to 

 discover what determines coloration in fruit, and 

 why the colour should show from year to year 

 such remarkable variations in one and the same 

 variety ; but its efforts so far have been unsuccess- 

 ful, and the information that science can give on 

 this subject is scarcely worth the attention of the 

 grower. 



There is, however, another aspect of the 

 -American type of monograph well exemplified in 

 this book which deservies nothing but praise and 

 emulation. That is the resolute thoroughness 

 with which fundamental problems are envisaged. 

 For example, we in this country are content to 

 recognise that certain varieties of apple do well 

 in certain districts and badly in others. We may 

 go so far as to make inquiry on the subject and 

 publish the results — a work upon which the Fruit 

 Committee of the Royal Horticultural Society is 

 now engaged. The American does better than 



I this. He endeavours to discover what are the 



f NO. 2431, VOL. 97] 



soil requirements of different varieties of apple, 

 and in this inquiry he is, apparently, so successful 

 that he is able to speak of and describe a "Bald- 

 win " soil, a " Northern Spy " soil, or a Rhode 

 Island "Greening" soil. 



So excellent are the brief introductory chapters 

 on selection of site and adaptation of varieties 

 to soil that we can imagine some strenuous urban 

 .American exclaiming on reading them : " Sure, 

 I can grow apples," and forthwith setting out 

 and growing them — perhaps successfully. 



Needless to say, the chapters on spraying and 

 on insect and other pests are well done. Lime- 

 sulphur increases yearly in favour with American 

 growers, and, indeed, the spraying schedule re- 

 commended by the College of .Agriculture of 

 Cornell University comprises four annual spray- 

 ings with lime-sulphur, to which, if insects are to 

 be destroyed as well as parasitic fungi, arsenate 

 of lead is added. 



The subject of breeding- is treated somewhat 

 briefly ; Mendelism is glanced at. The state- 

 ment (p. 425), "A breeder cannot obtain wholly 

 new characters in apples by making Mendelian 

 combinations," requires elaboration if it is not 

 to be misleading; and the list (p. 414) "showing 

 both self-sterile and self-fertile varieties" appears 

 to contain only shy, average, or prolific pollen- 

 bearers. It is curious that little or no reference 

 is made either to the history and origins of the 

 apple nor to recent work, as, for example, that 

 conducted by the Duke of Bedford and Mr. 

 Spencer Pickering at Woburn on economical 

 methods of planting. 



The book is well written by the hand of 

 an expert. It should meet with w^ide success 

 in America, and should be read with attention 

 by all interested in fruit-growing in this country. 



F. K.' 



THERMOD YNA MIC C HEM IS TR Y. 

 An Introduction to the Principles of Physical 

 Chemistry from the Standpoint of Modem 

 Atomistics and Thermodynamics. By Prof. 

 E. W. Washburn. Pp. xxv + 445. (New 

 York : McGraw-Hill Book Co. ; London : Hill 

 Publishing Co., 1915.) Price .155. net. 

 n^EACHERS and students alike should be 

 ^ grateful to Prof. Washburn for supporting 

 the use in physical chemistry of the differential 

 and integral calculus, which he introduces freely 

 in the work now under review. Students will be 

 surprised when they see how little calculus they 

 need, and how much that little will strengthen 

 the grip they get of physical chemistry. The time 

 required for acquiring the necessary knowledge 

 of calculus is nothing compared with the time 

 wasted in wading through the tedious mathe- 

 matics involved in evading the calculus. It is 

 not only a waste of time — it is also misleading — to 

 subject a number of difficulties each to a separate 

 treatment, as is done when no calculus is used, 

 as if they were of several quite distinct kinds in 

 cases where they might be ranked together and 

 enfiladed in a single attack. 



