SCIENTIFIC LITERATURE. 



277 



A valuable series of archseological in- 

 vestigations is chronicled in a tasteful 8vo 

 entitled The Hill Caves of Yucatan* The 

 author, who is Curator of the Museum of 

 American and Prehistoric Archaeology at the 

 University of Pennsylvania, had had his eye, 

 so to speak, on the Central American hill 

 caves for several years. The expedition was 

 at last made possible by the munificence of 

 Mr. J. W. Cor with, of Chicago, its purpose 

 being to search for new evidence of man's 

 antiquity in the caves of Central America. 

 The party landed at Progreso, and rapidly 

 made their way into the interior. The coral- 

 line and porous Mesozoic limestone of that 

 part of Yucatan had not been upheaved or 

 faulted, and, save for the waves of the hill 

 ridges, lay as it was deposited. The caves 

 were found to open vertically down into the 

 ground like wells, the shaft having evidently 

 been formed by the natural weathering down 

 of a level rock surface until a hole in the 

 roof of the cave was produced. These caves, 

 of which a number were examined, were 

 found in some cases to contain rude inscrip- 

 tions on the walls, in all cases a large num- 

 ber of broken potsherds, and in the excava- 

 tions conducted in the layers of rubbish 

 which made up the floor of the caverns, 

 charcoal and ashes, mixed with potsherds of 

 many makes and some bones, but no arrow- 

 heads, spear points, or even flakes of horn- 

 stone. Some human bones scattered in the 

 rubbish indicated that the old inhabitants of 

 Yucatan practiced cannibalism. Taken as a 

 whole, the antiquities show us the ancient 

 cave visitor as an agriculturist rather than a 

 hunter, although he seems not to have pos- 

 sessed domestic animals. The author, in 

 closing, says : " An earlier people visiting 

 Yucatan under its present topographical 

 conditions must needs have left traces in 

 the caves; because the undisturbed earth 

 beneath the culture layer discovered always 

 failed to show trace of any deeper, older, 

 or more primitive human visitor, the con- 

 clusion was that no such earlier people had 

 seen the region while its stony hills, its 

 torrid plain, and its damp caves were as 

 they now are." The book, aside from its 



* The Hill Caves of Yucatan. By Henry C. 

 Mercer. Philadelphia : J. B. Lippincott Co. Pp. 

 183. Price, $3. 



archaeological value, is of interest as giving 

 a picture of the geography and people of 

 that portion of Yucatan. It is very well 

 illustrated. 



One of the most beneficent services ren- 

 dered by modern science consists in supply- 

 ing a basis of exact knowledge for those 

 necessary arts that have been carried on by 

 empiric methods for centuries. Among the 

 most ancient of these arts is that of utilizing 

 the milk of our flocks and herds, for which 

 a scientific basis has only recently become 

 available. It is the purpose of the book 

 before us * to give the chemistry and bac- 

 teriology of the several processes of the 

 dairy. The author first describes briefly the 

 cow's udder and its process of secretion, and 

 then passes to the composition of milk, giv- 

 ing the percentage composition of the milk 

 of a number of animals, with a discussion of 

 the variations observed, and a table of the 

 legal standards in England and many of the 

 United States. After setting forth some of 

 the causes that influence the yield and qual- 

 ity of milk, he passes to the subject on 

 which science has been able to give the most 

 practical knowledge to the dairyman — bac- 

 teria. It is bacteria that cause milk to be- 

 come ropy or viscous to turn blue, red, or 

 yellow, to acquire a bitter taste, and to un- 

 dergo fermentative curdling. Bacteria also 

 are indispensable in the making of butter 

 and cheese. Pure cultures of these organ- 

 isms are used in dairies all over the north of 

 Europe for ripening cream, and our author 

 urges his fellow-countrymen not to be behind 

 the foreigner in this matter. After discuss- 

 ing the essential features of the formation 

 of butter and cheese, including the process 

 of churning and the action of rennet, he 

 gives the usual modes of testing milk, and 

 closes with a chapter on milk as a food. 



Convinced that throughout Europe there 

 must have existed systems of picture wi-iting 

 such as survive among primitive races, Mr. 

 Arthur J. Evans, the keeper of the Ashmo- 

 lean Museum, has made extended explora- 

 tions in Crete which have brought to light 



* Milk : its Nature and Composition. By C. 

 M. Aikman. Pp. 180, 12mo. London : Adam & 

 Charles Black. New York : Macmillan & Co. 

 Price, gl.25. 



