1869.] 



Dr. Thudichum on Luteine. 



253 



I. (c Researches conducted for the Medical Department of the 

 Privy Council, at the Pathological Laboratory of St. Thomas's 

 Hospital/'' By J. L. W. Thudichum, M.D. Communicated by 

 John* Simon, Esq. Third Series. — Results of Researches on 

 Luteine and the Spectra of Yellow Organic Substances con- 

 tained in Animals and Plants. Received November 11, 1868, 



1. Name. — Various parts of animals and plants contain a yellow crystal- 

 lizable substance which has hitherto not been defined, and to which, from 

 its prominent property, I assign the name of " luteine." 



2. Occurrence, — It occurs normally in the corpora lutea of the ovaries 

 of mammals, in the serum of the blood, the cells of the adipose tissue, and 

 the yellow fat of the secretion of the mammary gland, or butter ; in mam- 

 mals it occurs abnormally in ovarian tumours and cysts, and in serous 

 effusions. It is a regular ingredient of the yelks of the eggs of oviparous 

 animals. In the vegetable world it is observed in seeds, such as maize ; in 

 the husks and pulps of fruits, such as anatto ; in roots, such as carrots ; 

 in leaves, such as those of the coleus ; and in the stamina and petals of a 

 great variety of flowers. 



3. Properties. — Luteine is easily soluble in alcohol, ether, and chloro- 

 form, but is insoluble in water. It is soluble in albuminous liquids, such as 

 the contents of ovarian cysts and the serum of the blood. All these solu- 

 tions are yellow ; but the chloroform solution when concentrated has an 

 orange-red colour. 



4. Spectrum. — The spectrum of these solutions is distinguished by great 

 brilliancy of the red, yellow, and green part, and by three absorption-bands, 

 which are situated in the blue, indigo, and violet part of the spectrum. 

 The positions of the absorption-bands vary a little with the different 

 solvents. 



Orario-luteiiie 

 in alcohol. 



Egg-luteine 

 in ether. 



5. Crystallization. — The crystals of luteine are apparently rhombic 



plates, as shown in the accompanying figure, of which two or more are 



