OLEUM MORRHUM. 379 



PISCES. 



Isinglass The swimming bladder or sound of 

 various species of Acipenser, prepared and cut into 

 fine shreds. 



Characters. Light, coriaceous, whitish or yellowish, semi- 

 transparent, inodorous, tasteless ; insoluble in cold water, soluble 

 in 24 parts of boiling water, forming a transparent jelly on 

 cooling. 



From Isinglass is made : Solution of Gelatine. 



USE. 

 Isinglass is nutrient, Gelatine is used in chemical testing. 



Oleum Morrhuse COD-LIVER OIL. The oil 

 extracted from the fresh liver of the cod, Gadus 

 Morrhua, by the application of a heat not exceeding 

 180. 



Characters and test. Pale yellow, with a slight fishy 

 odour, and bland fishy taste. A drop of sulphuric acid added 

 to a few drops of the oil on a porcelain slab develops a violet 

 colour, which soon passes to a yellowish or brownish-red. 



Composition. Cod-liver oil consists chiefly of olein and 

 margarin, but contains as much as 5 per cent, of free fatty 

 acids (oleic, palmitic, stearic), traces of iodine and bromine, 

 the ordinary inorganic salts 01 animal tissues and products, and 

 trimethylamin N(CH 3 ) 3 . Some authorities give bile as a con- 

 stituent of cod-liver oil, others deny this entirely. 



Impurities. Inferior oils. 



Dose. 1 to 8 fl.dr. 



ACTION AND USES. 

 1. IMMEDIATE LOCAL ACTION AND USES. 



The action and uses of oils externally have been fully dis- 

 cussed under the head of Oleum Olivce, page 284. 



Cod-liver oil is sometimes rubbed into the skin of wasting 

 children as a nutrient, and with perfect success; but it im- 

 parts an objectionable colour and smell to the body. 



With a little perseverance, it is as easily taken as other 

 oils, and more easily digested, on account of the amount of 



