246 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



a living study, raising it above the dry bones of a matter to be learnt 

 because one must, and appealing to the young inquiring mind, which 

 is always wanting to know how a thing works, if the mind is a normal 

 one. The whole book is well thought out, clearly written, and one we 

 can recommend to teachers seeking a guide in this subject. 



" A First Book of Rural Science." By J. J. Green, B.Sc. 8vo. 

 viii -f- 146 pp. (Macmillan, London, 1913.) is. 6d. 



This is an excellent little book on plant life and the soil, with reading 

 matter and suitable practical exercises designed to enable the young 

 student to gain a knowledge of the way a plant lives, and of the treat- 

 ment of its environment to enable it to thrive in the best way. It is 

 suitable for use in evening continuation schools, and even for the 

 upper classes of elementary schools. 



" Illustrated Key to the Wild and Commonly Cultivated Trees 

 of the North-Eastern United States and Adjacent Canada." By 

 J. F. Collins and H. W. Preston. 8vo. vii -f- 184 pp. (Holt, New 

 York, 1912.) Cloth $1.35; leather $2.50. 



This little book with limp cloth covers and rounded corners is 

 intended as a pocket companion for those whose wanderings take them 

 among the trees of the district of which it treats, and who desire to 

 know the names of those they meet with. We have tested it for one 

 or two North American trees and find it " runs them down " with ease. 

 It should prove very helpful in America, and will be of use in Britain 

 in getting at the names of many introduced trees. 



" Growing Crops and Plants by Electricity." By E. C. Dudgeon. 

 8vo. viii + 36 pp. (Rentell, London, 1912.) is. net. 



Miss Dudgeon has rendered a service to horticulturists by bringing 

 together a brief account of what has been done in a practical way in 

 applying electricity to the growing of plants. An account of the 

 application of high-tension electricity to field crops and of electric 

 light to plants in houses is given with weights, &c, obtained. Miss 

 Dudgeon's own experiments have been . mainly with the mercury 

 vapour lamp, and the results she gives as to the acceleration of germina- 

 tion and growth are often remarkable. It would have been helpful 

 if she could have gone into greater detail, for the use of a mercury 

 vapour lamp would be comparatively simple. The average maximum 

 and minimum temperatures are given for the houses taken at 9 a.m., 

 but nothing shows what effect the lamp had in raising the temperature 

 while it was alight. We do not find what precautions were taken to 

 see that the water in the soil was kept even, nor do we discover whether 

 the moisture in the air was the same in both cases. In one case the 

 produce from twelve pea seeds (54 pods) is compared with that from 

 five (19 pods), but apart from the fact that these are very small yields 



