CHEMICAL SCIENCE. 185 



labourers first remove before they begin their attack on the guano. 

 In Bome places, as at Pabellon. de Pica and at Punta Grande, the 

 deposits lie under a mass of sand descended from the neighbouring 

 mountains ; and on this subject an observation made by M. F. de 

 Rivero is extremely curious. At the places above mentioned the 

 lowest guano deposits are covered with a stratum of old alluvial soil ; 

 then comes another layer of guano, and then a stratum of modern 

 alluvial soil. To understand the importance of this fact, our readers 

 must keep in mind that the age of the modern alluvions does not 

 extend beyond our historical times, while old alluvions date from 

 the period immediately preceding that at -which man first began to 

 inhabit the earth ; so that the guanaes, or cormorants and other 

 allied tribes of birds which deposit guano, must have existed thou- 

 sands of years before man, seeing that the inferior layer of guano is 

 several yards (sometimes from 15 to 20) in depth, and the old alluvial 

 crust above it has a thickness of upwards of three yards. 



To explain the immense accumulation of guano in these regions, 

 M. Boussingault observes that there has been a combination of a 

 variety of causes favourable both to its production and preservation. 

 Among these causes must be reckoned a dry climate ; a ground pre- 

 senting a vast number of chinks, fissures, and caverns, where the 

 birds can rest, lay their eggs, and hatch them without being disturbed 

 by the strong breezes from the south ; and then abundance of the 

 food suited to them. Nowhere is fish so abundant as on this coast, 

 where whole shoals of them are cast upon the shore even in fine 

 weather. Antonio de Ulloa states that anchovies especially are in 

 such abundance here as to defy description ; and he gives a good 

 account of the manner in which their numbers are diminished by the 

 myriads of guanaes which are seen sometimes flying in countless 

 flocks, like clouds intercepting the sun's rays, and sometimes darting 

 into the sea to catch their prey. According to M. Boussingault's 

 calculation, 100 kilogrammes of guano contain the nitrogen of 600 

 kilogrammes of sea-fish ; and as the guano deposits, before they 

 began to be worked, contained 378,000,000 of metrical quintals of 

 guano, the birds must have consumed 2,268,000,000 of quintals of 

 fish. — Atlas Journal. 



FORMATION OF TABTARIC ACID FROM MILK-SUGAR. 



Liebig gives a detailed description of the formation of Tartaric 

 Acid by the oxidation of Milk-sugar by nitric acid. He discusses 

 the mode of occurrence and constitution of tartaric acid, and several 

 allied vegetable acids, and mentions an experiment in which he tried 

 the action of aldehyde on cyanogen dissolved in water, in the expec- 

 tation of effecting the synthesis of malic acid. It gave, however, an 

 unexpected result. A flask containing about two quarts of water 

 was saturated with cyanogen, about an ounce of aldehyde added, 

 and the whole left in a cool place. The fluid remained clear and 

 colourless ; but gradually a mass of white crusts separated at the 

 bottom of the flask, which were found to be oxamide. The liquid, 

 saturated for a second and third time with cyanogen, yielded fresh 



