THE CESTRUS-PRODUCING HORMONE 91 



agents to which it is resistant include NaOH (230), and sodium 

 methylate and butylate (166, 167). Similar results have been 

 reported by Payne, Peenan, and Cartland (511). Mild 

 saponification is now a part of many routine methods of pre- 

 paring the hormone. 



Volatility and sublimation. The hormone is non- volatile and 

 does not sublime (346). 



Adsorption. The hormone is very readily adsorbed. Thus 

 the precipitation of the proteins from liquor folliculi removes 

 much of the hormone as a result of adsorption. According 

 to Laqueur (357), the hormone is readily adsorbed by dialysing 

 membranes and by filter paper. 



Action of ultra-violet light. Jordan and Doisy (317) report that 

 preparations of oestrin in petroleum ether, or in solutions 

 containing fluorescent substances, lose their activity on 

 exposure to light. The destruction is more rapid in ultra-violet 

 light or direct sunlight, but may also occur in diffuse light. 



[c] ADMINISTRATION 



Tissue implants. For testing pieces of tissue too small 

 to extract, and also to save chemical treatment, Zondek and 

 Aschheim (650) have used a method of intra-muscular implanta- 

 tion. This technique consists in the implantation of a small 

 piece of the tissue to be tested into a muscle. No graft is formed, 

 the implanted tissue is reabsorbed, and with it any active 

 substances present. The procedure is similar in principle to 

 the subcutaneous injection of tissue macerated in saline, which 

 is usually the first step in investigating the activity of a 

 tissue. The technique has obvious limitations, impracticabihty 

 of repeated administration, for instance, but valuable results 

 have been obtained by the method, notably the discovery of the 

 ovary stimulating properties of the anterior pituitary body. 



Oral administration. It is generally agreed that amounts of 

 oestrin known to be active by other means of administration 

 have no activity by mouth. Five tests were made by Allen (24) 

 of administration by stomach tube, and uniformly negative 

 results were found. Loewe, Tange, and Faure (409) report that 

 large doses up to twenty times the normal amount are required 



