3° 



PHARMACEUTICAL BACTERIOLOGY 



and which substance he named Bathyhius Hmckelii. This supposed deep 

 sea hfe was found to consist largely of colloidal deposits. The 

 theory of spontaneous generation is fully disproven though considerable 

 effort has been expended in an attempt to form a Hving substance in the 

 laboratory. Recently Dr. Burke claimed to have succeeded in instilling 

 life into gelatine ^lutions by means of radium, but this proved to be an 

 error. 



BiitchU's "artificial protoplasm" was once of considerable laboratory 

 interest, but it was not intended that this substance (an emulsion of oil) 

 should be considered as being endowed with hfe. The artificial continua- 

 tion of tissue growth according to the laboratory methods of Dr. Carel and 

 others, of course, has no bearing on the creation of hving cells by labora- 

 tory methods. 



According to the theory of universal evolution, the origin of bacteria 

 was simply an incident in the series of events (electronic) which resulted in 

 the development of the particular substances which occur in that particular 

 group of organisms, and the theory could be appended to the preceding 

 one or to the one which follows, since there is nothing in the concept of 

 universal evolution which conflicts with the ideas therein presented. 



5. The Colloid Theory. — The word colloid is derived from the latin 

 coUo (glue) and was applied by Thomas Graham, the father of colloidal 

 chemistry, to non-crystahzable substances of low diffusibility and gener- 

 ally of great viscosity, and other characteristic properties. Graham's 

 experiments on dialysis and the general properties of colloids, were read 

 before the Royal Society of London in 186 1, from which it becomes evident 

 that colloidal chemistry is the youngest of the modern sciences. The still 

 more recent investigations in the field of colloids has been fruitful in sug- 

 gestions and theorizations regarding the nature of living organic substances. 

 In order to comprehend the basic principles of the colloid theory of living 

 matter, it is necessary to set forth the fundamentals of colloids. Gelatine 

 may be taken as a type of colloidal matter. Colloids never crystallize, 

 they will not pass through animal membranes. A colloid dissolved in 

 water is designated a "sol," and as water is gradually abstracted the sol 

 changes into a "gel." A sol is a colloid system consisting of two phases, 

 the continuous phase called the dispersing medium or dissolving medium, 

 and the disperse phase or the colloidal particles in solution. Two classes 

 of colloids are of special importance to biology, namely the emulsoids and 

 the suspensoids. The emulsoids are viscous, gelatinize readily and are 

 not easily coagulated by electrolytes. Among the important emulsoids 

 are gelatine, agar, albumin, histons, and other proteins. The suspen- 

 soids do not gelatinize, they are not viscous, but are readily precipitated 

 by electrolytes. Among the suspensoids are the sols of metals generally. 



