862 



POPULAR SCIEXCE MONTHLY. 



right, with the confusion of right and left 

 which one first feels on using a mirror for 

 toilet purposes. 



School ConditioBS and Eyesight. — Dr. 



Brudenell Carter has taken up the question 

 of the effect of school conditions on the eye- 

 sight, particularly as to whether they develop 

 and aggravate short-sightedness and the 

 other defects of vision which have been 

 charged to them. He examined 8,125 chil- 

 dren in twenty-five elementary schools of 

 London. In forty per cent of them the eyes 

 were right. The others were subjected to 

 further special examinations. The author 

 reports, as the general result of his investiga- 

 tion, that the proportion of cases of myopia 

 was small, and that it bore no relation what- 

 ever to the lighting of the school ; the two 

 schools in which the greatest proportions of 

 defective visions were found being respect- 

 ively the best lighted and the worst lighted 

 of the whole number. No evidence was 

 found of progressive myopia. Some of the 

 worst cases were found among children who 

 had recently joined school, and there was 



nothing to show that it increased with the 

 length of time the children had been at 

 school. The proportion of cases of astigma- 

 tism was less than the proportion discovered 

 in Dr. Carter's private practice among 

 patients examined for every kind of optical 

 weakness. The vast majority of optical de- 

 fects were due to hypermetropia. The most 

 unexpected result of the investigation was 

 the discovery that a very large proportion of 

 the cases of defective vision were due, not to 

 structural defects in the refractive combina- 

 tions of the eye, but to imperfect practice in 

 seeing. Comparing the vision of children at 

 a country school with the cases in the town 

 schools, the author found the country vision 

 much better. It is inferred that vision is 

 strengthened by the habit of looking at ob- 

 jects at a distance, which are presented far 

 more frequently in the expanses of rural 

 landscapes than in the street-bounded sights 

 of the town. Dr. Carter recommends that 

 the vision be tested and trained systemat- 

 ically ; that it be included among the phys- 

 ical faculties that are tested by competition 

 and for proficiency in which prizes are given. 



MINOR PARAGRAPHS. 



The recent death of Lord Lilford, Thomas 

 Lyttleton Powys, at the age of sixty-three, 

 has removed one of the most devoted and 

 conscientious of English ornithologists. He 

 was interested in natural history from his 

 earliest years, and was President for many 

 years of the British Ornithologists' Union. 

 His collection of live animals at Lilford Hall 

 was widely celebrated. At the time of his 

 death — which occurred at Lilford Hall on 

 the I'Zth of June — he was engaged on a 

 large work on the Birds of the British Is- 

 lands. 



Geology has sustained a severe loss in 

 the death of Sir Joseph Prestwich, which 

 occurred on June 23d. He was born at Clap- 

 ham on March 12, 1812. He was engaged 

 in business in London until sixty years of 

 age, but during this time was able to gain 

 such a reputation among geologists that upon 

 the death of Prof. Phillips he was elected to 

 the chair of Geology in the University of Ox- 

 ford. His work as a pioneer in establishing 

 the geological antiquity of man was recog- 



nized by the Royal Society in awarding to 

 him a Eoyal medal in 1865. He continued 

 to be a prolific writer up to the time of his 

 death. Although he belonged to the old 

 school of " catastrophists " which Sir Charles 

 Lyell opened war on in 1830, and which to- 

 day is a rapidly decreasing minority, he did 

 much valuable and lasting work. 



An ingenious method of destroying cattle 

 ticks is described by Dr. M. Francis, a veter- 

 inarian of the Texas experiment station. 

 After several unsuccessful attempts to de- 

 stroy the ticks by various other means, the 

 dipping process was adopted, and after try- 

 ing several carbolic and arsenical solutions 

 with unsatisfactory results, the cattle were 

 forced to swim through a large vat of five 

 thousand gallons capacity, on the surface of 

 the water in which was a layer of cotton-seed 

 oil, from three quarters to one inch in thick- 

 ness, so that when they emerged they were 

 perfectly covered with oil. It is well known 

 that grease or oil of almost any kind is fatal 

 to insects, lice, etc., and the above treat- 



