54 



SCIENCE. 



[N. S. Vol. II. No. 28. 



had been previously done, and the impor- 

 tance of this formation in Iowa, a fact that 

 we are just beginning to appreciate, is still 

 further brought out. 



W. H. Norton, ' Certain Devonian and 

 Carboniferous Outliers in Eastern Iowa,' 

 pp. 117-133. Both these foi-mations are 

 represented east of their main areas, biit 

 whether the outliers have or have not been 

 cut off by erosion is still undecided. 



J. L. Tilton, ' Geological Section along 

 Middle Eiver in Central Iowa,' pp. 137-146. 



C. R. Kej^es, ' Glacial Scorings in Iowa,' 

 pp. 149-165. The paper describes and tabu- 

 lates strife in all four quarters of the State. 

 The general directions are between south 

 and east. 



W. H. Norton, ' Thickness of the Paleo- 

 zoic Strata of Northeastern Iowa,' pp. 169. 

 This important paper is based on well rec- 

 ords obtained from holes sunk both for water 

 and oil or gas. These valuable records are 

 usually so evanescent that to have so many 

 preserved is a matter of congratulation. 



C. R. Keyes, ' Gj^asum Deposits of Iowa,' 

 pp. 259-304. This report is a welcome ad- 

 dition to the scanty literature of an impor- 

 tant industry. Iowa is now fourth among 

 the States as a producer of plaster and has 

 great reserves of the crude rock for the 

 future. 



C. E. Keyes, ' Geology of Lee County,' 

 pp. 307-407. Lee county forms the soxith- 

 eastern corner of the State. The paper re- 

 views its geology with thoroughness and 

 with good illustrations. 



C. E.' Keyes, 'Economic Geology -of Des 

 Moines County,' pp. 411-492. This county 

 adjoins Lee on the north. After an intro- 

 ductory geological sketch, the biiilding 

 stones, clays, coal and other minor economic 

 minerals are taken up. 



The typography and general style of the 

 volume are excellent and reflect credit on 

 the management of the Survey. Since its 

 issue Dr. C. R. Keyes has become State 



Geologist of Missouri, and H. F. Bain has 

 become Professor Calvin's chief assistant, 

 making thus some recent changes of per- 

 sonnel in the staff. J. F. Kemp. 



HYGIENE. 



Anmial report of the Department of Health of 

 the City of Chicago for the year ended De- 

 cember SI, 1894.. Arthur R. Reynolds, 

 M. D., Commissioner of Health, Chicago. 

 1895. 268 pp., 8°. 



Dr. Reynolds remarks that "the phe- 

 nomenal healthfulness of the city continues 

 to be the theme of incredulous comment by 

 less favored localities." When a death rate 

 of 15.24 per 1,000 is reported for a city of a 

 million and a half of people it is very apt 

 to be the subject of incredulous comment 

 by statisticians, who are skeptical about 

 municipal death rates of less than 17 per 

 1,000, knowing that there are several ways 

 of lowering death rates besides the primitive 

 one of reducing the number of deaths. It is 

 clear, however, that there were but 23,892 

 deaths reported in Chicago during the year 

 1894 as against 27,083 in 1893; 26,219 in 

 1892, and 27,754 in 1891, and that, there- 

 fore, the death rate must have been com- 

 paratively low last year, as it was in almost 

 all large cities. 



The account of the small pox epidemic 

 is interesting. 2332 cases were received 

 in the city small pox hospital. 993 of these 

 had been vaccinated after some fashion, and 

 of these 161, or 16.2 per cent., died. 1339 

 had not been vaccinated, and of these 485, 

 or 36.2 per cent., died. The difference was 

 most marked in the children under 6 years 

 of age, in whom the mortality of those vac- 

 cinated was 12.5, and of those unvaccinated 

 44.0 per cent. The chronological summary 

 of Chicago mortality from 1851 to 1894, 

 with diagrams, is interesting and valuable. 

 The report, as a whole, contains a vast 

 amount of information and is highly cred- 

 itable to the department which issues it. 



