425 



terior extremity of the abdomen, receives two long caeca, which 

 may be traced forwards, one at either side of the body, till 

 they terminate anteriorly by entering the basal joint of the 

 first pair of legs. A large central nervous mass may be easily 

 demonstrated. It is placed near the middle of the cephalotho- 

 rax, of a somewhat stellate figure, with four pyriform lobes, 

 from which nervous filaments pass off to the surrounding parts. 

 The reproductive system is very obscure ; to it, however, 

 may probably be referred a pair of tubular organs, placed in 

 the anterior part of the abdomen, terminating at one end in a 

 cul de sac, which contains a striated, curved body, and appa- 

 rently opening at the other upon the surface. The larva is 

 hexapod. The structure of the oral organs is similar to what 

 occurs in Gamasus. 



Sir Robert Kane read a paper on the composition of the 

 essential Oil of the Laurus Sassafras, and of certain compounds 

 derived from it. 



This oil, which has a specific gravity of 1087, boils at 

 438° Fahr. By fusion with potash it is not acidified. Its com- 

 position was found to be expressed by the formula Coo Hio O4, 

 the same as that obtained by Saint Evre for the stearopten, 

 with which it is consequently isomeric. 



When this oil is treated with chlorine, a great deal of 

 muriatic acid gas is produced and given off, and finally a very 

 thick liquid is produced, which requires to be kept for a long 

 time at a temperature of boiling water to free it from the ex- 

 cess of muriatic acid gas ; the same may be done by washing 

 with a small quantity of water of ammonia, and then expa^ 

 sure to a moderate temperatupe, when the chlorine com- 

 pound can be obtained again, quite anhydrous. Its formula 

 is found to be C.20 Ha O4 CI4. When this body is heated to 

 about 350° of Fahr., it suddenly and violently decomposes, 

 gives off much muriatic acid, and deposits a large quantity of 

 charcoal. 



