June 21, 1889.] 



SCIENCE. 



487 



numbers of the Review. The Rev. H. P. Dunster argues for an 

 extension of the postal service, in a paper entitled " An Agricul- 

 tural Parcels Post," in which he maintains that the post-office 

 should give facilities for the distribution of food. E. N. Buxton 

 contributes an eminently readable article on " Sardinia and its 

 Wild Sheep," descriptive of a hunt in the wilds of Sardinia. Lord 

 Ebrington describes a " By-Election in 1747," giving the full de- 

 tails of the expenses of parliamentary methods more than one 

 hundred years ago, and throwing much light on early politics. The 

 number concludes with a long essay by Professor Huxley on " Ag- 

 nosticism and Christianity," written in his most characteristic vein, 

 which forms an important contribution to the already extensive 

 list of papers on this subject published in this Review. 



— Messrs. Longmans, Green, & Co. send us the first number of 

 ■the New Review, a magazine of ninety-six pages, which is sold for 

 the low price of fifteen cents. The prospectus lays great stress on 

 the eminence of the contributors that have been engaged, and con- 

 veys possibly the impression that the writer's name will be con- 

 sidered of more account than the quality of his work. However, 

 the articles in this first issue are on the same level as those of its 

 larger rivals, though some of them are too brief for a proper pre- 

 sentment of the subject treated. The opening paper, on " Gen. 

 Boulanger," is the best, and will of course attract the most atten- 

 tion. It is in two parts. The first, written with the general's own 

 authority and presenting his side of the case, is by Alfred Naquet 

 of the French Senate ; the second, presenting the opposite side, by 

 Camille Pelletan of the French Chamber. It appears that the 

 general's followers are animated by dislike of parliamentary gov- 

 ernment, and, though professing to be republicans, they really 

 want a sort of dictatorship tempered by the plebiscite. French 

 parliamentarism has not been so successful as might be wished, 

 owing to the fact that the ministry are not at liberty to dissolve the 

 Chamber and appeal to the people ; but to seek a remedy, as M. 

 Naquet would do, in the virtual abolition of parliamentary govern- 

 ment, seems very unwise. M. Pelletan thinks the rise of Boulan- 

 gism an almost unaccountable phenomenon, but attributes it partly 

 to the discontent which various classes feel towards the present 

 government, and partly to the passion of the French people for a 

 hero. It is plain, from the tone of the two articles, that the gen- 

 eral's partisans are more hopeful than his opponents ; and the out- 

 come of the struggle will be looked for with much interest. The 

 second paper in the Review is a rambling dialogue, " After the 

 Play," by Henry James, designed as a critique of the contemporary 

 drama. Earl Compton writes of " The Homes of the People," 

 presenting anew the evils of the tenement-house system in cities, 

 and advocating the erection of new and improved dwellings by the 

 ■cities themselves. Lord Charles Beresford writes on " National 

 Muscle ; " Mrs. Lynn Linton, on " The Religion of Self-Respect ; " 

 -a;nd Mr. G. W. Russell, on " The Unionist Policy for Ireland." 

 Mr. Russell's paper, though brief, is very suggestive, advocating 

 measures for assisting the Irish tenants to purchase their holdings, 

 and also a system of local government for Ireland similar to that 

 already established in England. The concluding article is by 

 Lady Randolph Churchill, detailing her observations during a 

 month in Russia. It is written in a clear and simple style, and 

 shows great keenness of observation, and will be sure to interest 

 those who like to read about social life and customs. On the 

 whole, the New Review, notwithstanding the brevity of some of 

 its articles, promises to be a formidable rival of the older English 

 reviews, as well as of some published in the United States. 



— European scholars are devoting much attention at present to 

 the centenary of the French Revolution and its influence upon 

 European politics. The Fortnightly Review for June (New York, 

 Leonard Scott Publication Company, 29 Park Row) opens with two 

 papers on the Revolution, — the first, " What the French Revolu- 

 tion did," by Frederic Harrison, a brilliant and scholarly paper ; 

 and the second, by Gen. Viscount Wolseley, entitled " The French 

 Revolution and War," in which he investigates the influence which 

 that event exerted upon the science of warfare. The Marquis of 

 Lome presents a review of " Five Years' Advocacy of Provincial 

 Parliaments," which he suggested some time since as a solution of 

 the Irish difficulty ; William Day, in a paper on " Turf Reform," 



argues for the necessity of devising fresh regulations, and institut- 

 ing more stringent measures for purifying the turf and benefiting 

 the whole racing community ; E. C. K. Conner writes on " The 

 Foreigner in England," and maintains that there are many serious 

 grievances arising from unrestricted immigration to England, call- 

 ing for immediate action on the part of the authorities ; Professor 

 E. A. Freeman contributes a note on " The House of Hapsburg in 

 South-eastern Europe," in which he questions some statements 

 made by Mr. J. D. Bourchier in a paper on the same subject in the 

 March number of the Review ; Lady Dilke describes some benefit 

 societies and trades unions for women, — a subject of much im- 

 portance to all laboring women ; Dr. Robson Roose presents some 

 good and careful rules on the " Art of Preserving Life ; " an anon- 

 ymous writer criticises some recent changes made by the British 

 Government in the matter of the Egyptian bonds ; and Frederick 

 Greenwood contributes an interesting sketch entitled " A Conver- 

 sation in a Balcony." The number concludes with an eminently 

 readable paper on " The Women of Spain," by Emilia Pardo 

 Bazan. 



LETTERS TO THE EDITOR. 



* t.*Corresfiondents are requested tobe as brief as possible. The "writer's naTne it 

 in all cases required as proof of ^ood faith. 



The editor will be glad to publish any queries consonant with the character of 

 t/ie journal. 



Cloud and Fog. 



The formation of cloud has been generally ascribed to the rising 

 of a mass of saturated air to a cooler stratum, where the cooling 

 due to expansion and that from the surrounding air produces a 

 supersaturation and visible cloud. Not long since, Mr. John Aitken 

 of Scotland propounded the rather startling theory that cloud could 

 ttot be formed without the intervention of solid particles of dust, 

 smoke, or other substance. This view was based on laboratory 

 experiments, in which dust-free air seemed to show no condensa- 

 tion upon rarefaction. It would seem as though this view can hardly 

 be possible. If two molecules of vapor have been sufficiently 

 cooled, why may they not coalesce into a double molecule of water .'' 

 If we consider that each double molecule of water needs a solid 

 particle for a nucleus, there will be needed enormous quantities of 

 these particles in each cloud, and more, it would seem, than can 

 possibly be present in the cloud-forming strata. 



A few experiments have been tried in cloud-formation, and a 

 brief review of these is given here, the complete discussion and ex- 

 perimental proofs being reserved for another occasion. Most of 

 the experiments were made with a clear glass water-bottle holding 

 a half-gallon, and having three openings at the top. These were 

 fitted with absolutely tight rubber stoppers having openings, which 

 allowed the use of wet and dry thermometers to determine the 

 moisture, and the use of glass tubes whereby the air could be com- 

 pressed or exhausted at pleasure. An attempt was made to satu- 

 rate the air by first passing it through a bottle of water ; but, this 

 not succeeding, it was passed through a bottle full of cracked pum- 

 ice and water, a U-tube of the same, another U-tube having cot- 

 ton soaked in water, and a straight tube with four inches of cotton 

 (also wet). Near the compressor was a tube having three inches of 

 dry cotton, and in the tube passing into the bottle there was an- 

 other pledget of cotton. It was still found, after passing through 

 this mass of moisture, that the air was not saturated, and it seems 

 a practical impossibility to perfectly saturate air. Even after heat- 

 ing the bottle and tube of pumice nearly to boiling, the air was not 

 saturated. It would seem as though this might explain in part the 

 non-success of some former experiments in producing cloud in 

 dust-free air. 



Experiment i. — Air was introduced into the bottle, as near 

 saturated as possible, and then the whole was heated to 1 10°. The 

 dry bulb rose a little faster than the wet. On suddenly cooling the 

 outside, no cloud was observed, nor did the thermometers come 

 together, but moisture was deposited on the sides. 



Experiment 2. — The air was again heated to no", and it was 

 mingled with nearly saturated air at about 65". No cloud was ob- 

 served. 



Experiment 3. — The air was again heated, and a small piece 

 of ice was suspended near the top. No cloud was observed, but a 



