272 



THE POPULAR SCIENCE MONTHLY. 



The two volumes before us on " Light " 

 and "Heat" are of the usual character. 

 The name of Professor Barrett as editor 

 may be taken as a guarantee that the vol- 

 umes are accurate in their statements, but 

 we see no evidence that the editorship goes 

 any further. They seem to be ordinary 

 text-books merely reduced in dimensions. 

 Good teachers might use them, we think, 

 with good effect, but good teachers are few, 

 and the best teachers are independent of 

 their books. On the other hand, bad teach- 

 ers are innumerable they are the rule, and 

 the real question about primary books is 

 how they work in the hands of incompetent 

 teachers. The best books in these circum- 

 stances are those that favor the self-educa- 

 tion of the pupil, and release him from the 

 over-meddling of stupid instructors. The 

 books before us, it is needless to say, are 

 not of that order. 



Die chemische Ursache des Lebens theo- 

 retisch und experimented nachge- 

 wiesen. (The Chemical Cause of Life 

 theoretically and experimentally demon- 

 strated.) By Oscar Loew and Thom- 

 as Bokorny, of Munich. Munich, Bava- 

 ria. 1881. Pp. 60, with a Colored 

 Plate. 



Since the first synthesis of an organic 

 body, urea, was made by Wohler in 1828, 

 say the authors of this treatise, vital force 

 has been regarded as the result of chemical 

 and physical processes. This has been ac- 

 cepted as satisfactory till the present time, 

 notwithstanding it has been necessary to ad- 

 mit, on a closer consideration, that a clear- 

 er definition of the chemical activity by 

 which living protoplasm is governed would 

 be hailed as a very desirable step of prog- 

 ress. The idea that there was a chemical 

 difference between dead and living proto- 

 plasm never found expression till 18*75, and 

 nearly all physiologists still hold the view 

 that a complete chemical identity exists be- 

 tween them, notwithstanding that it would 

 be hardly possible to explain the cause of 

 life if this were the case. E. Pfliiger was 

 the first to assert, in 18*75, in a paper on 

 physiological combustion in living organ- 

 isms, that a chemical difference must neces- 

 sarily exist between living and dead proto- 

 plasm. One of the authors of this treatise, 

 in verifying an hypothesis he has proposed on 



the formation of albumen, met with a number 

 of unaltered Aldehyde groups which stood 

 in close relations with the Amidon groups, 

 and immediately conceived the idea that the 

 source of the vital movement in protoplasm 

 was to be sought in the Aldehyde groups 

 with their intense atomic movements, and 

 the origin of death in the passage of the Al- 

 dehyde groups into Amidon groups. Short- 

 ly afterward both the authors succeeded in 

 demonstrating the real existence of Alde- 

 hyde groups in living plasma. The present 

 monograph gives a full and connected ac- 

 count of their experiments, and of the veri- 

 fications of them. 



The Oyster Industry. By Ernest Inger- 

 SOLL. Washington : Government Print- 

 ing-Office. Pp. 251, with Forty-two 

 Plates. 



The present monograph is a part of a 

 series on " The History and Present Condi- 

 tion of the Fishery Industries," which is in 

 course of publication under the direction of 

 the United States Fish Commission, in con- 

 nection with the census. The arrangement 

 of the main part of the work is geograph- 

 ical, beginning with the maritime provinces 

 of Canada, and passing, with copious ac- 

 counts of the culture and trade in oys- 

 ters at all important points on the Atlantic 

 coast, to the Gulf of Mexico and the Pacific 

 coast. Chapters follow on the utilization 

 of oyster-shells, and the natural history of 

 the oyster, with notices of the fatalities to 

 which it is subjected. " An Oysterman's 

 Dictionary " offers an entertaining as well 

 as informing collection of phrases and words 

 descriptive of mollusks and other inverte- 

 brates of the Atlantic coast. Statistical ta- 

 bles are given in the final chapter. 



A Monograph of the Seal-Islands of 

 Alaska. By Henry W. Elliott. Wash- 

 ington: Government Printing-Office. Pp. 

 176, with Two Maps. 



The fur-seal was very often mentioned 

 in the discussions that took place during the 

 negotiations for the acquisition of Alaska, 

 but very little was known of it, and it was 

 hardly represented in the best zoological 

 collections. The author of this monograph 

 became interested in the subject, and in 

 1872, by the joint action of the Secretary 

 of the Treasury and Professor Baird, was 



