Deposited from Metastable Solutions of Inorganic Colloids. 25 



The examination of the contents of the tubes and the deposits in them 

 under the microscope were commenced on May 29, 1913, that is about seven 

 months after they had been filled and sealed and sterilised. 



The peculiar growths shown in some of the appended microphotographs 

 were then seen in all the tubes examined, more abundantly in the "yellow " 

 solution tubes than in those containing "colourless" solution, but still plentiful 

 in these also. The tubes in the windows were richer in growth than those 

 kept in darkness, but the latter did contain growths also, and it would be 

 impossible without more evidence to say whether the greater result in the 

 windows might not be due to greater diurnal fluctuations of temperature than 

 those that take place in the dark cupboard. 



The chief appearances observed in the contents of these tubes are : — 

 (1) Patches of sometimes fine, sometimes coarse, granular deposits with fine 

 fibres running in them. (2) Chains of dots, sometimes slightly elongated, 

 like micrococci or short bacteria. (3) Branching coarse fibres like hyphae 

 of a fungus. (4) Coarse fibres, sometimes rounded, sometimes flat and 

 twisted like a cotton fibre ; these are very long, and sometimes run more 

 than the whole diameter of a low-power field, sinuous on their course and 

 quite unlike anything crystalline ; as mentioned earlier, these may be 

 adventitious. (5) Excessively fine fibrils, also very long and often taking the 

 most fantastic shapes, sometimes they form a network like a fibrin network, 

 at other times they are single and convoluted into the most intricate knots 

 or loops ; this type of fibre is finer than any cotton or silk fibre. 



All the tubes were examined carefully, but it would serve no purpose to 

 write a detailed description of each, as the appearances were so similar ; 

 so the following descriptions may serve as examples : — 



Tube No. 11 (West window, Yellow solution, no soda). Examined May 29, 

 1913. — This shows plenty of both fine fibres and masses of debris, and small 

 black dots, sometimes in rows like cocci. A very good dip is obtained from 

 supernatant fluid, near wall of tube, away altogether from the coarse deposits, 

 showing very fine branching and interlacing fibres, like minute hypha?. 



Tube No. 17 (West window, Yellow solution, plus soda). Examined May 29, 

 1913. — This is very similar to the above and contains both types of fibres. 



Tube No. 26 (East window, Yellow solution, plus soda). Examined May 30, 

 1913. — Very rich, both in fine, interlacing fibres and in the long, coarse, and 

 twisted fibres. The latter do not give any cellulose reaction with iodine and 

 sulphuric acid. Also, they are yellow hued and evidently contain colloidal 

 iron. Other slides examined give the same results. Many long, delicate 

 fibres often twisted into intricate loop patterns. Only yellow in colour ; no 

 iodine staining. The sulphuric acid appears to dissolve out much of the 



