xxxii GENERAL SUMMARY OF SCIENTIFIC AND 



quently boiling the same portion with permanganate, a def- 

 inite one for each animal fluid tested. He can thus discrim- 

 inate between a spot of milk and one of white of egg upon a 

 cambric handkerchief. 



In Agricultural Chemistry a vast store of material has 

 been accumulated. Pfeffer has apparently settled the vexed 

 question which of the colors of the spectrum was most act- 

 ive in the decomposition of carbon dioxide in the leaves of 

 plants. He exposed the leaves in a tank of water to a spec- 

 trum 230 millimeters long, and measured the action by count- 

 ing the bubbles evolved in a given time. He ascertained that 

 the maximum decomposition takes place at the maximum of 

 light-intensity near D toward E. Calling the decomposition 

 in the yellow 100, that in the red was 25.4, in the orange 65, 

 in the green 37.2, in the blue 22.1, in the indigo 13.5, and in 

 the violet 7.1. The curve of these members closely agrees 

 with Kerordt's curve of the intensity of light. These results 

 entirely confirm those of Draper published many years ago. 

 An important experiment in practical agriculture has been 

 carried on for two years and more at the Massachusetts Agri- 

 cultural College, under the direction of Dr. C. A. Goessmann, 

 Director of the chemical departments. This experiment is 

 the cultivation of the best European varieties of the sugar- 

 beet upon the experimental farm, and their subsequent anal- 

 ysis in the laboratory, in order to settle the question of the 

 profitable manufacture of beet-root sugar in the Northern 

 States. The best variety for different climates and soils, the 

 best methods of cultivation, the time of harvesting, and the 

 most suitable methods of extracting the sugar all these are 

 questions which Dr. Goessmann seems likely to solve in a 

 manner at once satisfactory and profitable. 



In Mineralogy we have the usual announcements of new 

 species, and new determinations of the chemical composition 

 and crystallographic peculiarities of the old ones. The na- 

 ture and character of the immense meteorites found in Green- 

 land several years ago by the Swedish expedition continue 

 to invoke the attention of scientific men ; and numerous me- 

 moirs have been published upon the nature of the iron and the 

 other constituents, the amount of occluded gases and their 

 peculiarities. 



In economical mineralogy a most important announcement 



