ABOUT LOBSTERS 91 



exist various recipes for such artificial sea water. In 

 these experiments, two of these were examined, i.e., the 

 mixture of van Deurs and a mixture by Schmaltz. Al- 

 though both mixtures have been found satisfactory, the 

 one by Schmaltz is recommended, chiefly because this 

 mixture comes a bit closer to the composition of natural 

 sea water than that of van Deurs. The Schmaltz recipe 

 is as follows: 



Sodium chloride (NaCl) 14.52 lbs. 



Magnesium sulphate (MgSo 4 ,7H 2 0) 3.52 lbs. 



Magnesium chloride (MgCl 2 ,6H 2 0) 2.86 lbs. 



Calcium chloride (CaCl 2 ,^H 2 0) .7 lb. 



Potassium chloride (KC1) .33 lb. 



Total approximately 22 lbs. 



The specified amounts of salt are mixed with 92 

 gallons ordinary drinking water [check to see that it has 

 not been chlorinated]. It is necessary to stir the solu- 

 tion at regular intervals until all the salt has been 

 dissolved. This process takes about two hours. The vari- 

 ous salts can be obtained from chemical firms and be 

 used successfully, although they often cause some tur- 

 bidity in the solution as some of the substances may not 

 be water soluble 



All the salts, with the exception of potassium chlo- 

 ride, can be stored for a considerable length of time, 

 even when mixed, provided they are kept in a dry place. 

 Potassium chloride is highly water absorbent and even 

 in ordinary air very soon liquifies. It is therefore sug- 

 gested to buy this salt immediately before use and take 

 out only the amount needed for one mixture unless it is 

 kept in a tightly closed glass jar. 



Apart from experiments with the above mentioned 

 two recipes, experiments have also been carried out 

 with plain water to which was added various kinds of 

 ordinary salts, mainly because these ordinary salts have 

 been used commercially in storage water with little or 



