PHYSIOLOGY OF THE INVERTEBRATA. ii 



Albumins are incapable of being crystallised, or, if they 

 are present in some tissues in an apparently crystalline 

 condition, they are not crystals in the true sense of the word. 

 These pseudo-crystals are readily recognisable beneath a 

 microscope, for they dissolve in a dilute solution of potash, 

 and are stained yellow by nitric acid. 



A solution of iodine colours albumin or protoplasm brown, 

 while sulphuric acid colours it red. Carmine deeply stains 

 dmd protoplasm, but has no action on living protoplastm. 

 Dilute mineral acids and alcohol coagulate albumin ; but it 

 is soluble in concentrated hydrochloric acid. According to 

 Dr. F. Hoppe-Seyler,* albumin has a specific rotatory power 

 of from- 35.5° to- 56°. A temperature of about 50° 0. co- 

 agulates albumin ; i.e., it is converted into an isomeric modi- 

 fication by the action of heat, as well as by dilute acids, as 

 already stated. 



Albumin combines with hydrochloric, sulphuric, phosphoric, 

 and acetic acids, forming albuminates. It also combines with 

 certain bases and salts, forming similar compounds. It was 

 the albuminate of potash which gave Lieberkiihn the means 

 of ascertaining the empirical formula of this complex chemical 

 compound. Lieberklihn's formula for albumin is represented 

 as follows : — 



CyjHuj'NjjOjjS. 



The above formula gives no idea of the atomic constitution 

 of albumin. 



Dr. 0. Schorlemmer, P.E.S. (Rise and Development of 

 Organic Chemistry, p. 1 23) says : " The enigma of life can only 

 be solved by the discovery of the synthesis of an albuminous 

 compound.'' The direct synthesis of albumin has not yet 

 been performed ; but during the past nine or ten years some 

 excellent work has been done by Loew and Bokorny in this 

 line of research, which opens a vast field of inquiry for 

 the physiological chemist. These chemists have paved the 



* Handhucli tier Physiolor/tsch- unci Pathologisch-CIiemischen Analysf. 



