312 



NATURE 



{Feb. 6, 1879 



" Bind up those tresses : O, what love I note 

 In the fair multitude of those her hairs ! 

 Where but by chance a silver drop hath fallen, 

 Even to that drop ten thousand wiry friends 

 Do glue themselves in sociable grief, 

 Like true, inseparable, faithful loves, 

 Sticking together in calamity." 



"A more exact method" (of measuring the viscosity of 

 gases) "is to place timed chronometers under bell-jars 

 containing various gases, and also t'n vacuo ^^ (p. 19). 



"Diffusion of Gases into Gases.— The unhampered 

 diffusion of gases into gases has been little studied" 



(P- 39). 



" Experiments show that the more a gas is soluble in a 

 liquid the more is the liquid volatile in the gas " (p. 45). 



" Whether the feeling called pitch depends upon the 

 appreciation of the rapidity of sequence or upon the 

 duration of each distortion of the ear-drum is not easy to 

 decide, for the one is the inverse of the other. Perhaps 

 the fact that a single long wave produces a different im- 

 pression from that produced by a single short wave, and 

 that this difference reminds one of the differences between 

 grave and shrill notes, may be regarded as evidence that 

 duration of individual impression rather than rate of 

 sequence is to be considered as the origin of pitch" 

 (p. 77)' 



After reading these statements, we have come to regard 

 it as a decided merit, that in this book on Molecular Physics 

 we are not told anything about molecules. The value 

 of the book would be increased by cutting out " Molecular 

 Physics" from the title, together with everything in the 

 book included under that heading, and devoting the whole 

 book to Practical Physics as adapted to the capacities 

 and opportunities of young students. 



J. Clerk Maxwell 



Oi/R booh: shelf 



The Journal of the Royal Agricultural Society of 

 England. Part II. (London : John Murray, 1878.) 



This is no ordinary number of an agricultural journal. 

 It is, in fact, a memoir on the agriculture of Eng- 

 land and Wales, prepared under the direction of the 

 Royal Agricultural Society, and presented by them at the 

 International Congress held in Paris during the present 

 summer. The memoir is now issued as the second part 

 of the Society's Journal for the current year. 



The memoir is well worthy of the Society under whose 

 auspices it has appeared. It forms a large volume of 

 over six hundred pages, and contains ten treatises on 

 different aspects of English agriculture, each the work of 

 a distinct author. 



The first article in the memoir is a " General View of 

 British Agriculture," by Mr. Caird. He commences with 

 statistics as to the home and foreign supply of food, then 

 glances at the changes introduced in agriculture during 

 recent years by the increased use of machinery, and of 

 artificial foods and manures, and last, though not least, 

 by free trade. After a very brief notice of the differences 

 of climate and soil in England he comes to his main sub- 

 ject — "the landed property of England," its character, 

 distribution, ownership, improvement, value, and relation 

 to Government. The whole essay is written with remark- 

 able ability, and is full of important information. 



The second article is on " English Land-law," by F. 

 Clifford and J. A. Foote. It treats of succession, tenan- 

 cies, agreements, leases, and recent legislation on the 

 subject of unexhausted improvements. The third article 

 is by Capt, Craigie ; it deals with "Taxation," and de- 

 scribes the various kinds of taxation, and their incidence 

 on the various classes connected with agriculture. This 



is followed by a short paper on "Farm Capital," by 

 E. P. Squarey. 



The fifth article is by much the longest in the volume ; 

 it has for its scope the whole subject of " Practical Agri- 

 culture " ; it is written by Mr. J. A. Clarke. The article 

 commences with a sketch of the climate and geology of 

 England, and then proceeds to give statistics as to the crops 

 produced, the number of live-stock maintained, the im- 

 ports of manure and food, and the prices of agricultural 

 products. Then follow chapters on the management of 

 cattle, sheep, and pigs, with*a description of the various 

 breeds of live-stock, including horses. Crops and manures 

 are then discussed, the practice of good farms in different 

 parts of England being indicated. The concluding chapter 

 is on machinery, and cultivation by steam. The whole 

 article covers nearly two hundred pages ; it is full of 

 practical information, condensed into a small compass. 



The sixth article treats of " Dairy Farming," and is 

 written by Mr. J. C. Morton ; to this is added an appendix 

 on "Pastoral Husbandry," by W. T. Carrington. Mr. 

 Morton, after reviewing the statistics of the subject, pro- 

 ceeds to describe the various breeds of cattle employed 

 for dairy purposes in England, illustrating this part of 

 his paper by wood-cuts. He then treats of the rearing of 

 calves, the sale of milk, and the production of cheese 

 and butter, describing in each case the practice of different 

 parts of the country. 



The seventh article treats of "The Cultivation of Hops, 

 Fruit, and Vegetables," and is the work of Mr. C. White- 

 head. It is naturally divided into three chapters. The 

 subjects are treated statistically and practically, and 

 much important information is given. 



The next paper is of special interest at the present 

 time, it is on "The Agricultural Labourer," and is writ- 

 ten by Mr. H. J. Little. The past history of the British 

 labourer is sketched, and his condition in various parts of 

 the country described. His earnings, expenses, domestic 

 life, education, and provident societies are treated of, and 

 evidently by one who can speak from personal knowledge 

 of the subject. 



The ninth paper is the only one of a strictly scientific 

 character ; it deals with the " Influence of Chemical 

 Discoveries on the Progress of Enghsh Agriculture," and 

 is the work of Dr. A. Voelcker. The scope of this paper 

 is hardly so large as its title, as the author generally limits 

 his remarks to investigations made since i860, and has 

 nothing to say of Continental discoveries. The paper is 

 for the most part an account of the investigations made 

 by Messrs. Lawes and Gilbert at Rothamsted, and of the 

 work done by the author himself. The subjects treated 

 of are — The Soil, Continuous Cropping, Manures, Im- 

 provement of Permanent Pastures, Feeding and Rearing 

 of Stock, Industries attached to the Farm, Experimental 

 Stations. 



The volume fitly concludes with an article on the history 

 and work of " The Royal Agricultural Society," written 

 by Mr. J. M. Jenkins, the Secretary of the Society. 



It will be seen that the [memoir issued by the Royal 

 Agricultural Society includes a wide range of subjects ; it 

 would be hard indeed to find another volume containing 

 as much information on English agriculture in the same ; 

 compass. The whole is published at the extremely low 

 price of six shillings . We trust that it will find a large 

 circulation R. W. 



A Visit to South America; with Notes and Observations 



on the Moral and Physical Features of the Country, 



and the Incidents of the Voyage. By Edwin Clark, C.E. 



(London : Dean and Son, 1878.) 



Mr. Clark's modest little narrative [,is considerably 



superior to the ordinary run of modern books of travel, 



which have become as plentiful, nearly, as novels, though 



we are glad to say, on the average, much more worth 



reading. Mr. Clark has ^certain scientific qualifications 



