FRAGMENTS OF SCIENCE. 



139 



Royal Commission on Tuberculosis in Ani- 

 mals the statement is made that ' the with- 

 drawal from dairies of every cow that has 

 any disease whatever of the udder would 

 form some approach to security against the 

 serious danger incurred by man from the use 

 of tuberculous milk, but it would not be an 

 adequate security.' The presence in a dairy 

 of a tuberculous cow, the report says, is a 

 decided source of danger to the public, espe- 

 cially having regard to what has been learned 

 respecting the rapid development of tuber- 

 culosis of the udder. Regarding the value 

 of tuberculin injections as a diagnostic agent, 

 the following resolutions were adopted at the 

 International Veterinary Congress held last 

 September, and hence represent the opinions 

 of the foremost veterinarians of Europe : ' No. 

 1. Tuberculin is a very valuable diagnostic 

 agent and can yield the greatest assistance 

 in combating tuberculosis. There is no 

 reason for objecting to its general applica- 

 tion on the ground that it may aggravate 

 pre-existing tuberculous lesions. No. 2. The 

 congress expresses the desire that govern- 

 ments shall order the employment of tuber- 

 culin in herds in which the existence of 

 tuberculosis has been established.' The offi- 

 cial veterinarians of Germany are advised to 

 use tuberculin, and are supplied with it at a 

 low cost from the government laboratories." 



Tibetan Women. — As described by Mr. 

 W. W. Rockhill, the Tibetan women are 

 usually stouter than the men, with fuller 

 faces, and do not entirely lose their good 

 looks before they are thirty or thirty-five 

 years old. They are as strong as or perhaps 

 even stronger than the men, because, being 

 obliged to do hard work from childhood, 

 their muscles are more fully developed than 

 those of the men, who do not carry water on 

 their backs, work at the loom, or tend the 

 cattle. Their hair is long and coarse, but not 

 very thick ; it remains black, or only mixed 

 with a little white, to extreme old age ; and 

 both men and women with white hair are 

 rarely seen. The skin of the Tibetan is 

 coarse and greasy, light brown in color, fre- 

 quently nearly white, except when exposed 

 to the weather, when it becomes a dark 

 brown, nearly the color of our American In- 

 dians. Rosy cheeks are common among the 

 younger women. The Tibetans' voices are 



powerful, those of the men deep, those of 

 the women full and not very shrill. Their 

 hearing is good, and they can converse free- 

 ly from one side of a valley to the other, a 

 distance of half a mile, without ever having 

 to repeat phrases or perceptibly raise the 

 voice. They can endure exposure without 

 any apparent inconvenience, the women do- 

 ing their work with the right side of the 

 body completely exposed, and small children 

 going naked, or with only a pair of boots on, 

 except in the coldest weather. They can 

 also endure hunger, and are at all times 

 small eaters. 



A New Glass Construction. — We take the 

 following from a report presented by Dr. 

 Schott to the French Society for the Encour- 

 agement of National Industry : For siliceous 

 glasses the expansion increases with the pro- 

 portion of alkali. Boric acid produces a 

 striking decrease of expansion. In super- 

 posing upon each other two glasses of dif- 

 ferent compositions, it is requisite that there 

 should exist a certain relation between the 

 relative thickness of the two layers of glass 

 and their coefficients of expansion. Thus at 

 Jena they solder normal thermometer glass, 

 the coefficient of cubic expansion of which 

 between 0° and 100° = 0-0000244, to an 

 aluminous sodium borosilicate, the expansion 

 of which = 0-00001'7'7. The former kind of 

 glass must be placed externally and the sec- 

 ond internally in order to form a hollow ves- 

 sel or tube. We may also join together three 

 or more layers of two or more glasses. Of 

 two layers of glass with different expansions 

 after cooling, that with the greatest expan- 

 sion will be in a state of tension and the 

 other in a state of compression. External 

 layers in a state of compression increase in a 

 striking manner the resistance of glass to 

 mechanical actions and to rapid changes of 

 temperature. Flasks thus manufactured 

 may be strongly heated (to a temperature of 

 184°), and may then be sprinkled with cold 

 water without injury. Such glasses are not 

 liable to the sudden rupture which is apt 

 to occur in glass tempered by the process of 

 De la Bastie. 



An African Village Scene. — " I doubt," 

 says Dr. D. Kerr-Cross, " if finer villages 

 or better built houses exist anywhere in un- 



