362 COLLOIDS IN BIOLOGY AND MEDICINE 



to paralyze the vessels (i.e., increased blood supply to the kidneys). 

 According to CERVELLO and Lo MONACO, chloroform checks caffeine 

 diuresis when simultaneously administered, but it has no influence if the 

 chloroform effect precedes the caffein. According to THOMPSON and 

 WALTI, atropine checks renal secretion and at the same time decreases 

 the amount of urea. According to H. LOWE the amount of urine se- 

 creted was not increased by the injection of pilocarpine, the sugar re- 

 mained unchanged, the uric acid was somewhat increased, phosphoric 

 acid was diminished greatly and the total nitrogen to some extent. 



It must be emphasized that we are here dealing with pure secretory 

 activity. The action of CO 2 on glycosuria may possibly be attrib- 

 uted, according to STOFFEL,* to changes in permeability, whereas 

 phloridzin diuresis is much more probably accounted for by a hin- 

 drance to the reabsorption of the sugar formed in the kidneys. 



Since our colloid-chemical knowledge in the realm of pharmacology 

 and toxicology is extremely restricted, we are limited to the few 

 short chapters which follow. It must be especially emphasized that 

 the most important territory, the specific nerve actions L (see note 

 on p. 352) is colloid-chemically still almost completely terra incognita. 



Toxicology and pharmacology study the action of chemical and 

 physical influences upon organisms, i.e., colloid structures. Aside from 

 general considerations, the action of suspensions and colloids upon the 

 body deserves our special attention. In the following pages, these 

 questions though apparently separated are to a certain extent sys- 

 tematically handled, yet this is upon superficial and not upon essen- 

 tially scientific grounds. 



Colloids. 



Pharmacy and therapeutics ever since the classic age have made con- 

 siderable use of colloids and suspensions, that is of the general colloidal 

 properties of substances which have absolutely no specific chemical 

 action. I do not refer to the containers for medicines, such as gelatin 

 capsules or wafers, but to the strongly adsorptive properties of 

 colloids and suspensions which guarantee a rapid action by reason 

 of their enormous development of surface. Colloids may serve to 

 correct the action of substances such as morphine, chloral, aloes, etc., 



1 We cannot always assume that it is a nervous effect when, among its other 

 actions, the substance involved acts upon the nerves. For instance, strong 

 coffee aids digestion. An investigation of Handovsky,* 2 based upon observations 

 of A. Pick, makes it probable that the cause may be found in a specific property 

 of caffeine, which raises the internal friction, i.e., the ionization of albumin. But 

 we know from page 156 that the disintegration of albumin starts with the forma- 

 tion of albumin ions, and we can consequently understand why caffeine and theo- 

 bromine, which is related to it, favor the digestion of albumin by pepsin. 



