1866.] MISCELLANEOUS. 77 



As a test for the preservation of color, the larvae of the tomato- 

 worm (Sphinx quadrimaculata') was used. These larvae are 

 difficult of preservation with the natural form and color, nearly 

 always turning dark brown and contracting badly in alcohol and 

 most other preparations. 



As a result of these experiments the following solutions were 

 found highly satisfactory in all respects when properly used. By 

 their use the larvae and recent pupae of the tomato-worm were 

 preserved and still retain their delicate green colors, together with 

 their natural form and translucent appearance, while the internal 

 organs are fully preserved. Fishes, mollusks, various insects, 

 worms, and leaves of plants have also been preserved with perfect 

 success and far better than can be done with alcohol. In the 

 case of mollusks, especially, the preparations are very beautiful, 

 retaining the delicate semi-transparent appearance of the mem- 

 brances nearly as in life, with but little contraction. Another 

 great advantage is the extreme simplicity and cheapness of the 

 solution. 



To use this fluid I prepare first the following stock solution, 

 which may be kept in wooden barrels or casks, and labeled : 



Solution A 1. 



Rock salt 40 oz. 



Nitre (nitrate of potassa) 4 oz. 



Soft water 1 gal. 



This is the final solution in which all invertebrate animals must 

 be preserved. A solution with double the amount of water may 

 be kept if desirable, and called^ A 2. Another with three 

 gallons of water will be A 3. 



In the preliminary treatment of specimens the following solution 

 is temporarily employed, and is designed to preserve the object 

 while becoming gradually saturated with the saline matter, for in 

 no case should the specimen be put into the full strength of solu- 

 tion A 1, for it would rapidly harden and contract the external 

 parts and thus prevent access to the interior. Even with alcohol 

 it is far better to place the object for a time in weak spirits and 

 then tranfer successively to stronger, and for some objects as 

 Medusae, no other treatment will succeed. 



