402 SUMMARY OF CURRENT RESEARCHES RELATING TO 



may be regarded as identical. It furnishes at the same time an objec- 

 tive proof of the practicability of the bacterial method for quantitative 

 photometric determinations. 



These figures confirm the long-known result that the energy of 

 gaslight falls rapidly at the most refrangible end of the spectrum, in 

 com2)arison to sunlight. This fall does not, however, appear to be so 

 rapid with the clear white flame of a large Sugg's burner as with a 

 Bun sen burner. 



The light of an Edison's lamp, produced by a constant stream 

 from twenty Grove's elements, has a similar effect to that of a Sugg's 

 burner. Their relative assimilating energies with a green alga 

 {Scenedesmus quadricaudatm) were determined immediately after one 

 another at four different spots of the microspectrum, as follows : — 



The absolute energy of Edison's lamp was somewhat less than that 

 of Sugg's burner. 



Microbia of Marine Fish.* — At the zoological station recently 

 established at Havre, L. Olivier and C. Eichet have carried on an 

 extensive series of experiments on the presence of microbia in the 

 tissues of living fish. With one or two exceptions, they find these 

 organisms universally present in the peritoneal fluid, the lymph, the 

 blood, and, in consequence, in the tissues. They have all the charac- 

 ters of terrestrial microbia, and are reproduced in the same way, by 

 division and by spores. They are most numerous in the peritoneal 

 fluid, less so in the blood and lymjih. 



The most common form is that of bacilli, longer or shorter, 

 endowed with oscillatory movements ; they are coloured by ammo- 

 nium picrocarbonate and by aniline pigments ; some are j)rovided 

 with sj)ores, either in the middle or at the extremity of the rod. 



Movements of Minute Particles in Air and "Water.f — C. v. Njigeli 

 discusses the laws which regulate the ascending, descending, and 

 dancing movements and the power of floating of minute particles in air 

 and water, as bearing on the question of the transport of the patho- 

 genous Schizomycetes. The movements depend entirely on currents 

 of air, combined, in the case of descending movements, with the attrac- 

 tion of the earth. If there is no current in the air below a certain 

 minimum rapidity, the air once free of fungus-germs must remain 

 free as long as these conditions last. This minimum raiiidity is 

 estimated at 2 cm. per second. The movements of minute jmrticles in 

 water are subject to much more complicated laws. The passage of 

 particles such as the Schizomycetes and other fungus-spores from 

 water to air takes place by the drying of moist surfaces, not by 

 simple evajjoration from the surface of a fluid ; also by the bursting 



* Comptes Rendus, xcvi. (1883) pp. 384-6. 



t Uutersuch. iiber niedere Pilze aus dem pflanzen-phys. Inst. Miinclien, i. 

 (1882) pp. 76-128. Sec Bot. Centralbl., xii. (1882) p. 345. 



