I50 



SCIENCE. 



[Vol. XII. No. 295 



assiz has been given. Its former existence was first clearly shown, 

 and its approximate limits roughly defined, by the late Gen. G. K, 

 Warren of the Engineers. A considerable arm or bay of this lake 

 extended up the Red River valley into Dakota and Minnesota. Its 

 ancient beaches are still easily discernible, and its bottom received 

 the deposits of sediment ground from the rocks by the great conti- 

 nental glacier upon whose western margin the lake was situated. 

 These deposits constitute those soils of the Red River valley which 

 have lately become so famous for their fertility. In co-operation 

 with the Canadian Geological Survey, in whose territory the greater 

 part of Lake Agassiz was situated. Professor Chamberlin's assist- 

 ant, Mr. Warren Upham, has made a study of the portions of this 

 lake-basin and of its branches which lie within the United States. 

 This work has already occupied Mr. Upham during several seasons, 

 and is still in progress, and has brought to light many instructive 

 and important facts. Examinations have also been made of the 

 glacial deposits in the Coteau du Plateau du Missouri of Dakota, 

 by Prof. J. E. Todd ; in northern Illinois and adjacent parts of In- 

 diana and Michigan by Mr. Frank Leverett ; in Wisconsin by Mr. 

 I. M. Buell ; in Indiana by Prof. L. C. Wooster ; and in Maine by 

 Prof. George H. Stone. Large and important additions have thus 

 been made to our knowledge of the distribution and action of the 

 ancient ice-sheet, and of the history of the continent during the 

 glacial period." 



Appalachian Division. — Classification of Soils. 



Probably the most important section of Major Powell's report is 

 that in which he announces a new, scientific, and systematic classi- 

 fication of soils. He has long been engaged in the study of this 

 subject, and has given his classification to some specialists and 

 institutions, but this is the first publication of it. It will attract 

 wide attention on account both of its scientific and its economic 

 importance. 



After briefly stating the progress of the geologic work of the year 

 in the Appalachian division, under the direction of Mr. G. K. Gil- 

 bert, Major Powell proceeds : " The soils of the region are derived 

 from the rocks. In part they are constituted by disintegrated rock 

 not otherwise disturbed, and holding its original position ; but in 

 part they also result from the transportation and sorting of disin- 

 tegrated rock by streams, waves, glaciers. The complete mapping 

 of the geologic features thus shows the distribution of the soils, and 

 it has been determined to separate the data concerning soils, and 

 prepare a soil-map to accompany each geologic map. The field- 

 parties gather data for both at the same time. 



" In planning this work it has been found necessary to adopt a 

 working classification of soils. The following is an exhibit of the 

 scheme. It is held only as a tentative classification, to be enlarged, 

 modified, or reconstructed, as the facts developed in the progress 

 of investigation may demand. 



" Eiidogenous soils are those derived from the country rocks, and 

 remaining in place. 



" Exogenous soils are those derived from other sources than the 

 country rocks proper to the district where the several soils are sit- 

 uated. 



"Endogenous soils are classed in conformity with the rocks from 

 which they are derived, as, 

 " I. Sandstone soils. 

 " II. Limestone soils. 

 " III. Granite soils, etc. 

 " Exogenous soils are classed as, 



" I. Alluvial soils ; i.e., those formed from deposits on flood- 

 plains made by running waters. 

 " II. Lacustrine soils ; i.e., those formed from deposits in 



lakes. 

 " III. Marine soils; i.e., those formed from deposits made by 

 the action of waves and currents along the shores of 

 the sea. 

 " IV. Drift soils ; i.e., those formed from deposits made by 



glacial agencies. 

 " V. Swamp soils ; i.e., those formed from deposits made in 



fresh-water swamps. 

 " VI. Marsh soils ; i.e., those formed from deposits made in 

 marine marshes. 



" VII. Dune soils; i.e., those formed from deposits of drifted 



sands. 

 " VIII. Volcanic soils ; i.e., those formed from volcanic 



ashes. 

 " IX. Overplacement soils ; i.e., those formed from rocks that 

 have been transported by gravity, as talus soils, land- 

 slide soils ; also those formed of alluvial cone rocks. 

 " Under the several species recognized above, important varieties 

 are found. 



" The classification thus briefly set forth seems to be natural,, 

 simple, and easily applied to the facts presented in field-study." 



Passing over a section on correlation of formations, under the 

 review of the work in the division of volcanic geology. Major 

 Powell says, " For nearly two years Captain Dutton has been occu- 

 pied in the investigation of the Charleston earthquake, and in pre- 

 paring a monographic report upon it. In many respects the best 

 observed earthquake that has ever occurred, and perhaps the most 

 carefully studied, it has yielded results which undoubtedly add to 

 our knowledge of such phenomena. But Captain Dutton, after 

 two years of laborious investigation, is still of the opinion that the 

 result adds but little to our knowledge of the ultimate causes which- 

 produce such catastrophes." 



The remainder of Major Powell's report includes a review of 

 geological work in connection with the Potomac formation and in. 

 Montana, and of the extensive paleontological investigations that 

 have been carried on. A review is also given of the work done in the 

 division of chemistry and physics, and the report closes with brief 

 notices of the illustrations division and of the library. 



HEALTH MATTERS. 

 Food- Preservatives. 



In a pamphlet on the effects of food-preservatives on digestive 

 agents, by Henry Leffman, M.D., and William Beam, M.A., the 

 authors say that the use of antiseptics in perishable articles of food 

 has become quite general in recent years, and has been to a certain 

 extent the subject of legislation. Salicylic acid has been probably 

 the most used ; and while the sanitary authorities in different coun- 

 tries have, as a rule, opposed its use, there has been no positive 

 evidence of its injurious action, even when continued for some 

 time. Lehmann published in Pettenkofer's Archives of Hygiene 

 several instances in which healthy male adults had taken for many 

 days considerable doses of this acid without apparent injury. 

 While there may be a legitimate field for the use of these agents in 

 articles of food of a highly perishable character, and especially 

 where the addition is made known, there can be no question that 

 their indiscriminate use is dangerous. Independently, however, of 

 any directly injurious action, it is important to inquire how far 

 they may interfere with the nutritive or medicinal value of any arti- 

 cles with which they may be associated. The matter has been 

 brought prominently to the notice of these chemists, in consequence 

 of some analyses made by them in which the free use of salicylic 

 acid in beers and malt extracts was detected. Similar results in 

 regard to beers were found by various State boards of health and 

 by the Department of Agriculture of the United States Govern- 

 ment. It becomes important to inquire how far the presence of 

 the substances may interfere with the diastasic action ascribed to- 

 preparations of malt. Of eleven samples tested, including all the 

 extracts widely known in this market, only four had any appreci- 

 able effect on starch, and but one of these was strikingly efficient. 

 They have undertaken to determine what retarding effect such 

 preservatives may possess. 



The antiseptics selected were salicylic acid, boric acid, sodium 

 acid sulphite, saccharine, beta-naphthol, and alcohol. The sample 

 of beta-naphthol was of the form now sold under the name ' hydro- 

 naphthol.' 



From the experiments it will be seen that salicylic acid prevents 

 the conversion of starch into sugar under the influence of either 

 diastase or pancreatic extract, but does not very seriously interfere 

 with peptic or pancreatic digestion of albumen. Saccharine holds 

 about the same relation as salicylic acid. Sodium acid sulphite 

 and boric acid are practically without retarding effect. Beta-naph- 

 thol interferes decidedly with the formation of sugar by diastase 



