Preparation of Sea Water for the Aquarium. 129 



Description of Figures, PI. I. 



Fig. 1. Vermidom of Protula Dysteri. 



2. Single calcareous tube with the worm protruded and ex- 



panded. 



3. An adult Protula extracted from its case, c. branchia, 



e. testes, d. ova, — (dorsal view). 



4. A Protula undergoing prolification (central view). 



5. The produced zooid just set free. 



6. Junction of parent and derivative zooids (ventral view), a. 



ciliated canal. 

 7- Pedal tubercle. 



8. Setoe and Uncini. 



9. Ciliated canal, greatly magnified. 



10. Ova — young and completely developed. 



11. Spermatozoa — young and completely developed. 



On the Artificial Preparation of Sea Water for the Aqua- 

 rium. By Geokge Wilson, M.D., F.R.S.E., Lecturer on 

 Chemistry.* 



In an interesting communication contained in the " Annals 

 of Natural History, for July 1854 (p. 65), Mr Gosse has recorded 

 the results of an important experiment on the possibility of arti- 

 ficially preparing sea water for Marine Vivaria, Guiding him- 

 self by Schweitzer's analysis of the water off Brighton, and ex- 

 cluding the less abundant ingredients, he employed chloride 

 of sodium, sulphate of magnesia, chloride of magnesium, and 

 chloride of potassium, t which were dissolved in a suitable 

 quantity of water. In April last various species of marine 

 plants and animals were introduced into this imitation sea 

 water, and as during a period of six weeks they "throve and 

 flourished from day to day, manifesting the highest health 

 and vigour," Mr Gosse draws the very natural conclusion, 



* Read to the Chemical Section of the British Association, September 1854, 

 t The following are Mr Gosse's exact directions : — Common table salt, 3 \ 

 ounces ; Epsom salts, \ ounce ; chloride of magnesium, 200 grains troy ; chlo- 

 ride of potassium, 40 grains troy. To these salts a little less than four quarts 

 of water were added. 



VOL. I. NO. I. — JAN. 1855. I 



