32 



HARDWICKE'S SCIENCE-GOSSIP. 



cochineal in ether, treating the residue with boiling 

 alcohol, allowing it to cool, and treating the deposit 

 with pure alcohol ; by then adding its own volume of 

 sulphuric ether a deposit of carminium is formed. 

 Carminium is iincrystallisable and of a beautiful red 

 colour ; it fuses at 104°. It is soluble in water, but 



Fig. 10. — Opvntia cochmillifera. 



not in sulphuric ether or in essential or fixed oils. 

 Nitric or hydrochloric acid, chlorine and iodine 

 when in a concentrated solution destroy carminium, 

 but when dilute only enhance the brightness of its 

 colour. If alkaline solutions are added to carminium 

 its colour changes to purple. It is precipitated by 

 lime water. 



When heated it is decomposed, but yields no 

 ammonia. Cochineal is principally used for dyeing, 



Fig. II. — Coccus cacti {m7>\c). Fig. 12.— C(7a?« £ra<:i'/ (female). 



and is employed chiefly in woollen goods ; the colour 

 is fixed by a mordant of alumina and oxide of tin, and 

 the colour is intensified by super-tartrate of potash. 

 Mixed with white it forms rouge ; and the colours, 

 carmine and lake are made from it. 



To make a single pound of cochineal it is 

 estimated th.at no fewer than seventy thousand 

 insects are required. It was once considered an 

 extremely precious article, fetching sometimes as 

 much as 36.?. and 39^, per lb., but the price is now4J. 

 Previous to 1845 there existed a duty on cochineal, 

 but it is now abolished. It does not lose its properties 

 as a dye by prolonged keeping, if in a dry place. 

 Hellot made some experiments on dried Cochineal 

 which had been kept more than one hundred years, 



and found their colour as rich as that from those jusi 

 obtained. 



Adulteration is effected by mixing the dried up 

 skins of old, used insects with the genuine article, 

 also by artificially representing them in paste, but 

 they can generally be easily detected. 



Another form of adulteration is sometimes 

 practised, and consists in mixing what is known ki 

 commerce as "East India Cochineal," and which is 

 a very inferior article with the real. 



THE ROMAUNT OF BEDEGAR. 



An Autobiography. 



By the Rev. H. Friend, F.L.S. 



\Continued from p. 11.] 



THAT you may see first of all how much atten- 

 tion was formerly paid to my ancestors, I 

 will tell you what one of the old writers on medi- 

 cine has to say about me. It is true that his 

 language is somewhat dry and uninteresting to many, 

 but, as we all feel a special pride in hearing what 

 people say about us, I may be forgiven if I am 

 somewhat vain of the learned names by which my 

 family has been ; distinguished. This writer, then, 

 in a brief chapter on Spina alba, says it is also 

 known as '■'' Akantha laike. Wood Cyanara (a name 

 which has since been applied to a relative of 

 the thistle family, and is specially associated with 

 the artichoke), Donacitis, Venus' Sceptre (so I 

 understand the name Eyysi sceptrum, which the 

 names Frawcn Distel and Mary's Thistle confirm). 

 White Thistle, Royal Thistle, Robber Thistle. In 

 Hebrew it may be called Atad laban, that is. Spina 

 alba. The German name is White Way-Thistle. 

 This is what the Arabs call Bedeguar; it is also 

 known as the Herb of the House or House-wort," — 

 I suppose because of the remarkable qualities attri- 

 buted to certain parts of the plant when employed as 

 a medicine. It should be observed that in the fore- 

 going account of my ancestors the maternal side is 

 especially referred to, since spina and acanthus are 

 both feminine. However, in later times, when people 

 began to think more of the father than of the mother, 

 one Galen adopted the masculine gender for this 

 name, and, when using it as one word, converted it 

 into Leucacanthon. Hence it is that we find this 

 term in very frequent use (not without a good deal 

 of confusion) among more recent authorities on 

 plants. I wish to impress upon my readers at this 

 point the important fact that, so far as we have 

 pursued my family history, every name which my an- 

 cestors received — whether Bedegar in Arabic, Acan- 

 thus in Greek, Spina in Latin, or Atad in Hebrew, 

 or Distel in German — had reference to the thorny or 

 prickly nature of the original plant. To make this 

 matter quite certain I have fortunately been able to 



