HARDWICKE'S SCIENCE-GOSSIP. 



125 



stand a few minutes, and you will see small Threads 

 or Filaments rising perpendicularly from the little 

 Bulb of Amalgama, and thrusting out from their 

 Sides little Branches in the form of a Tree." 



The "Iron Tree" can be made thus :— "Dissolve 

 Iron Filings in Spirit of Nitre, pour on Oil of Tartar 

 per deliquium, and a sort of Branches will be formed 

 and adhere to the Surface of the glass representing 

 Leaves and Flowers." 



The Arbor Veneris is supposed to be an entirely 

 new discovery, and the author affirms, from his own 

 experience, that it "is extremely wonderful and 

 pretty, and made with little Trouble. 



"In half an Ounce of Aqua Fort Is let a bright Half- 

 penny, or some, small piece of pure clean Copper 

 remain for about twelve Hours, and then take it 

 out. Dissolve a little Quicksilver in as small a 

 Quantity as you can of the same, or stronger Aqua 

 Fortis. The Solution will be white and like Flour 

 and Water, at which Instant it must be put into the 

 first Liquor, which will immediately become of a 

 lovely blue, and throw down something of a white 

 Sediment, but have very little Body or Consistence. 

 Have ready some Salt Ammoniac finely powdered, 

 whereof put in a very little at a time, stirring it 

 about until it dissolves, makes the mixture of a 

 blueish white, and gives it a Consistence of Starch, 

 which condition shews it to be fit for your 

 Purpose." 



A drop of this is to be placed on a piece of glass, 

 upon which a small piece of bright iron wire has 

 been previously laid, and in the course of a short 

 time " Bamifications of the purest Copper" will take 

 place. The cnly source of failure appears to be the 

 quality of the aquafortis. 



Another plan " was discovered accidentally by 

 the very ingenious Mrs. Colembine, of the City of 

 Norwich, in her search after new Colours from 

 Copper for painting in Miniature. The Scarlet 

 Dyers use in their Business Aqua Fortis saturated 

 with Tin, and make no secret of it ; but one of the 

 trade, who is thought to excel in the richness of his 

 Scarlet, prepares his Aqua Fortis after a manner 

 known only to himself. In some of this Mrs. 

 Colembine dissolved Copper, and happening to leave 

 a Piece of Iron in the mixture, she was surprised 

 with the Branchings from it, and shewed them to 

 my very ingenious Friend and Correspondent Mr. 

 William Arderon, F.R.S., who, by her Desire, sent 

 an Account thereof to me." 



The first part concludes with a notice " that those 

 who wish to keep the Solutions of Salts in Readi- 

 ness for Examination can be supplied with boxes, 

 Phials, and Slips of glass by Mr. Cuff, Optician, 

 against Serjeants Inn Gate in Fleet-Street. This i 

 may be an Ease to them, and 'tis hoped will prove 

 of some Advantage to him." 



FERTILIZATION IN CYPRIPED1UM. 



{Lady's Slipper.) 



rT!HE genus Cypripedium, according to the 

 J- arrangement of Lindley, constitutes the seventh 

 and last tribe of Orchidacese— viz. Cypripedia ; also 

 thus arranged in Hooker's translation from the 

 Frenclf of Le Maout and Decainee, in which the tribe 

 includes two other genera beside Cypripedium ; viz. 

 Uropedium and Selenipedium. The characteristics 

 of the tribe, as described in the latter book, are thus : 

 —"Anthers 2, lateral, both fertile, the intermediate 

 one petaloid ; pollen granular, softening during ferti- 

 lization ; stigma divided into 3 areolae, opposite to 

 the stamens." We at once perceive, by placing this 

 tribe by the side of the other tribes of Orchidacea;, 



a great difference in some of the 



(To he continued?) 



that there is 

 characters. 



Having then just glanced at the general characters 

 of the tribe, we will examine the individual parts of 

 the flower more closely, and try and make ourselves 

 acquainted with its structure, noticing as we pro- 

 ceed the difference between them and the analogous 

 parts of the flowers of other orchids. 



The perianth is superior and petaloid, composed 

 of two rows, the outer consisting of two parts 

 (sepals), one very large at the top, the other much 

 smaller below; the large one is really two which 

 have become united, as three is the normal type in 

 the outer row of the perianth in orchids ; the inner 

 row contains three divisions (petals); the two lateral 

 ones alternate with the sepals; the lower one, 

 termed the lip or labellum, is opposite the lower 

 sepal. The labellum is large and slipper-shaped, 

 —hence the common name "Lady's Slipper," with 

 three openings into the large cavity. One, the 

 largest, in the front, separated from the two lateral 

 ones by the inflexed edges of the labellum pressing 

 against the column ; these two lateral passages are 

 much smaller than the front one. The labellum is 

 without a nectar-sac or tube, so differing from most 

 orchids ; but there are slender hairs inside, lining 

 especially the basal part, bedewed with little shining 

 drops of liquid, apparently like nectar, but in which 

 Mr. Darwin could find no trace of crystallization 

 when dried. This is so much like nectar that it 

 would easily attract insects. The central body, 

 termed the column or gymnostegium, is rather short 

 and is not terminated by the anther as in other 

 orchids, but the anther is supplemented by a large 

 shield-like body, slightly notched at the top, and 

 with a larger notch at the bottom, dividing it into 

 two ear-like appendages. This is very prominent, 

 standing in front of the lateral passages, and partly 

 over the stigma. Anthers two, one on each side of 

 the style, behind the shield-like body, and midway 

 in the space occupied by the lateral passages. 

 Pollen granular, covered with a viscid substance 

 which is so sticky that it will pull into threads. 



