343 



lime in excess, when concentrated, (Ca. CI., CaO.) and thus, with- 

 out diminishing its activity in breaking up protein compounds, 

 allows the dry matter subjected to alcohol, or other solvents of 

 alkaloids, to remain permeable. When baryta or lime is subse- 

 quently employed to develop) the alkaloid, either with or without 

 ammonia salts, the chloride of calcium does not interfere, and 

 very pure alcoholic or ethereal solutions, can at once be obtained. 

 He added, that he wished to express his accordance with the 

 opinion of JNIr. Green, that the chemical experiments should be 

 so conducted in the search after poison,- which had caused death, 

 as to eliminate from the tissues that portion which had entered 

 them, as being distinct in its effects, from the remainder found in 

 the stomach, or intestines, uncombined with protein compounds. 

 In cases of poisoning by corrosive poisons, the parts destroyed or 

 altered are easily observed, and the results of many experiments 

 had led him to form the opinion, that the organic poisons, in their 

 actions, leave traces only little less strongly marked. 



Dr. Samuel Cabot, Jr., stated that a specimen of the 

 Ruddy Duck [Erismatura Dominica) of South America, 

 as is supposed, had been shot in a little bay upon the 

 northeast shore of Lake Champlain. It had never be- 

 fore been seen north of Jamaica. The specimen is in the 

 possession of Mr. Henry D. Morse, who intends to pre- 

 sent it to the Society. 



Dr. David F. Weinland read the following paper enti- 

 tled— 



THE PLAN ADOPTED BY NATURE FOR THE PRESERVATION OF 



THE VARIOUS SPECIES OF HELMINTHS, (Parasitic Worms.) 



It has been determined by the Helminthological investigations 

 of the past twenty years, that all Helminths have reproductive 

 organs, and produce eggs ; and that all those which have been de- 

 scribed as wanting these organs, and in whose cases the theory of 

 spontaneous generation has been applied, are the undeveloped 

 stages of other well known Helminths which have reproductive 

 organs. For instance, the whole order of Hydatids ( Cystica of 

 Rudolphi) are found to be larva3 of tapeworms, and the immense 



