7o6 



THE POPULAR SCIENCE MONTHLY. 



Nerves," by J. Rose Bradford, D. So. Nos. 

 5 and 6 form a double number, which con- 

 tains three papers : " On Digestion in Hydra, 

 with some Observations on the Structure of 

 the Endoderm," by M. Greenwood, with two 

 plates ; " On the Phenomena of Inhibition 

 in the MammaUan Heart," by Prof. John A. 

 McWilliam, M, D., with two plates ; and " On 

 the Normal Duration and Significance of the 

 ' Latent Period of Excitation ' in Muscle- 

 Contraction," by Prof. Gerald F. Yeo, M. D., 

 with cuts of tracings. 



Proceedings of the United States National 

 Museum^ Vol. X, 1S8Y, consists of technical 

 descriptions of fishes, birds, etc., illustrated 

 with thirty -nine plates and a number of 

 text-figures. Appended to the volume is a 

 " Catalogue of the Contributions of the Sec- 

 tion of Graphic Arts to the Ohio Valley Cen- 

 tennial Exposition, Cincinnati, 1888." These 

 contributions represent processes of engrav- 

 ing and printing for pictorial purposes from 

 the sixteenth century to our own time, wood- 

 engraving in the United States, etching in 

 the United States, and modern photo-me- 

 chanical processes. 



Tlie Report of the Entomologist, of the 

 Department of Agriculture, Prof. Charles V. 

 Riley, for 1887, is devoted chiefly to an arti- 

 cle by L. 0. Howard on the chinch-bug, giv- 

 ing a complete account of the species, and 

 an article on the codling moth by the same 

 writer. The use of the kerosene emulsion, 

 the only recently devised remedy for the 

 chinch-bug of any importance, is treated in 

 some detail in the first article. Other pa- 

 pers accompanying the report relate to silk- 

 culture, scale-insects, and other locally nox- 

 ious species, apiculture, etc. The report con- 

 tains eight plates, showing the insects treated 

 of, methods of fumigation, and the Cattaneo 

 mulberry-tree. 



In Hie Cat and its Diseases, Dr. B. M. 

 Hale, of Chicago, has published a useful 

 and convenient paper on this animal of high- 

 ly domestic habits and the treatment which it 

 is entitled to receive. Brief accounts are 

 given of the origin and history, traits, and 

 varieties of the cat. Under the heading of 

 " Health of Cats " are discussed their food, 

 including grass, their drink, housing, and 

 the care of their fur. Several diseases are 

 described, and the special treatment that 

 should be given for each. 



The report on Mineral Resources of the 

 United States, 1887, by David T. Day 

 (United States Geological Survey, 50 cents), 

 is the fifth of the series on this subject. It 

 extends the information contained in the 

 previous volumes to include the calendar 

 year 1887. The statistical tables have been 

 brought forward, but with this exception 

 only such information as is supplementary 

 to the previous volumes should be looked 

 for. The principal statistics concerning the 

 more important substances have already 

 been published in special bulletins. Prom 

 this report it appears that not only was the 

 production of iron and steel in the United 

 States very much larger in 1887 than in the 

 previous year, but we consumed virtually all 

 that we produced, besides many thousand 

 tons of old iron worked over, and imported 

 more than in any other year except 1880. 

 For several years we have consumed more 

 iron and steel than any of the great Euro- 

 pean countries. Our production of gold 

 shows a decrease of about two million dol- 

 lars from 1886, while silver shows an equal 

 increase. During the greater part of the 

 year the copper market was very dull, yet 

 our production shows an advance over the 

 highest previous figures. The output of 

 lead went far ahead of the largest previous 

 quantity. Zinc also shows an increased pro- 

 duction. While there was practically no 

 production of pure aluminum in 1887, the 

 amount of aluminum bronze produced has 

 risen from 4,000 or 5,000 pounds in 1885 

 to 144,764 pounds in 1887, and the amount 

 of ferro-aluminum from 2,500 pounds in 

 1886 to 42,617 in 1887. The total produc- 

 tion of all kinds of commercial coal shows a 

 marked increase, owing partly to the near- 

 by use of natural gas, stimulating coal to 

 seek more distant markets, and partly to the 

 advance in the iron manufacture. The re- 

 striction of the output of petroleum in the 

 Pennsylvania and New York fields was com- 

 pensated by the increase in the Ohio field, 

 with some help from West Virginia and 

 California. The consumption of natural gas 

 can be got at only approximately. The 

 amount of other fuel displaced by it, esti- 

 mated at the value of less than five million 

 dollars in 1885 and ten millions in 1886, had 

 risen to over fifteen millions in 1887. The 

 value of the precious stones produced in the 



