678 OYSTERS AND ALL ABOUT THEM. 



duce multitudes of microscopic insects, which furnish food 

 to other animals. These were not the only considerations 

 which induced the Messrs. Gasquet to establish themselves 

 on the Peninsula of Giens. The numerous kinds of shell- 

 fish which took refuge in the gulf and the fine oysters 

 occasionally found there were indications of the possibility 

 of success. 



In connection with the experiments of acclimation 

 which the Messrs. Gasquet have made on the shell-fish 

 brought from Cette, experiments which have given the 

 most favourable results, I have thought it would be inter- 

 esting to make known the chemical composition of the 

 waters of the breeding-pares. The following is an analysis 

 made in the laboratory of M. Schutzenberg, a professor in 

 the College of France : 



Sodium and Potassium . . . . . . . . 1 1-02 



Chlorine and bromine .. .. .. .. 21-61 



Magnesia 3-03 



Sulphuric acid .. .. .. .. .. 5-12 



Residuum for i liter (about I quart 61 cubic inches) 41-28 



With some slight differences, the water at Cette resem- 

 bles that at Giens. This fact must be borne in mind, for 

 it shows that the acclimation of foreign species can only be 

 obtained without difficulty, when the medium whence those 

 species are taken closely resembles that in which they are 

 to be placed. The water of the roadstead has a density of 

 3 by the hydrometer ; its temperature is very variable ; it 

 attains, and even exceeds, 24. This is not, however, an 

 unfavourable condition. Under the action of the heat and 

 the beneficial influence of the rain-water, the shell-fish 

 rapidly develop. 



