172 SCIENTIFIC MISCELLANEA. 



Assaying The quantity of alloy which silver contains, is determined by 



cupellation. The process consists in fusing the alloy with a certain propor- 

 tion of lead, upon a bed of bone ashes, termed a cupel. The oxidizable me- 

 tals enter into combination with the oxide of lead, and sink into the cupel ; 

 while the silver, which resists oxidation, remains in a brilliant globule on the 

 surface. The process is so elegant, so simple, and so rapidly performed, that 

 it has been generally adopted, not only by individuals, but by the different 

 European governments. It is a process, un fort umately, which is not deserv- 

 ing of confidence within less than 5 or 6 parts in a thousand. Alloys were 

 made, by M. d'Arcet, containing exactly 950, 900, and 800 thousandths of 

 silver, and samples of each sent to the principal assayers of Europe. Few of 

 the trials approached within less than 4 thousandths, and some not within 

 7 or 8, of the truth. In some future number of The Analyst we intend to 

 enter in detail upon this subject, which seems not to have excited that degree 

 of attention in this country which a matter of so much importance demands. 



B. 



Secretions of Vegetables — The following singular instance of secre- 

 tion in the economy of vegetation, observed in the Coryanthus maculata, a 

 native of Brazils, and belonging to that extraordinary class of flowers called 

 epiphytes, has recently engaged the attention of Mr. Murray, F.L.S. In this 

 remarkable flower, which refuses to open during cloudy or gloomy weather, 

 there are two glands, sufficiently conspicuous, from which a secreted liquid, 

 perfectly limpid and colourless, is incessantly distilling, day and night, for 

 the space of about three days, when the temperature of the air is consider- 

 able. The discharge is from the tips of the glands into the labellum or 

 pouch, and as soon as it reaches a certain level, the superfluity flows away by 

 means of certain ducts provided for that purpose. By the test of permuriate 

 of iron, and chloride of gold, conjoined with potassa, the presence of morphia 

 was ascertained ; and other tests, with litmus paper, determined it was a 

 super-salt of morphia — Dr. Edward Turner having stated that the liquid in 

 the ascidium of the Pitcher-plant, yielded, on evaporation, crystals of super- 

 oxalate of potassa, Mr. Murray states that in the very considerable number 

 of analyses which he has made of the liquid abstracted from unopen Ascidia, 

 or Pitchers, lime-water and chloride of platinum gave him indications of nei- 

 ther the one nor the other of these ingredients. Muriate of soda, malic and 

 other acids, and chromule, were the exclusive contents of the liquid of the 

 Pitchers. When the lid of the Pitcher opens, a more decided degree of 

 acidity, is soon manifested, from the contact of the atmosphere. 



In the 3rd vol. of Audubon's highly interesting Ornithological Biography, 

 the following passage occurs at p, 361 : — *' On opening several individuals [of 

 the Pied-billed Grebe, Podiceps Carolinensis} in different parts of the Union, 

 I observed in their gizzards a quantity of hair-like and feather-like substance 

 for which I could not account ; but which I at length found to be the down 

 of certain plants, such as thistles, the seeds remaining undigested and attach- 

 ed to it. My friend, Thomas Mac Culloch, made the same observation, on 

 examining some at Pictou, in Nova Scotia, and I have found similar sub- 

 stances in the stomach of many individuals of Podiceps cristatus" In the 

 description of the Rednecked Grebe, CP. i-ubricoUis, Lath.), in the Ornitho- 

 logical Dictionary, Montagu says : — " Upon dissection, the stomach was found 

 to be distended with feathers and small seeds. Being struck with so singu- 



