148 



Mr. W. N. Hartley on the 



[Feb. 8, 



prepared subsequently. It is at any rate satisfactory to know tbat it was 

 lifeless, and tbe only thing of the kind met with. It is impossible to get glass 

 apparatus quite clean by means of hot water ; those in the habit of making 

 organic analyses are acquainted with the large amount of dirt which can be 

 swept out of a tube by a plug of filter-paper or cotton-wool, after washing 

 with abundance of boiling water. 



Experimental Results. 



The ivhole of the tubes, an account of which here follows, were kept for 

 sixteen weeks at a temperature of 30° to 34° C. during the daytime, 

 and not lower than 20° 0. at night. A fluctuating temperature is 

 considered by Dr. Bastian to be favourable to evolutional changes*. 

 From the month of February till the time of examination the tempera- 

 ture would never be lower than 16° C, and was never higher than 

 30° C. 



A. A solution containing about 4 per cent, of a mixture of sodium di- 

 phosphate and amnionic tartrate, and having a neutral reaction, was placed 

 in three tubes, which were exhausted with a Sprengel, sealed up, and heated 

 for three hours to 150° C. Prepared on July 16th, 1870. 



No. 1. No trace of any organized matter discovered ; nothing but a little 

 silica dissolved out of the glass. Opened October 18th, 1870. Time kept 

 three months. 



No. 2. Examined July 17th, 1871. Kept over a year. No living or- 

 ganism found. In this tube the animalcule already mentioned was met 

 with. The liquid was turbid with silica. 



No. 3. Examined September 2nd, 1871. Kept a year and six weeks. 

 Nothing found. The silica makes these tubes troublesome to examine, on 

 account of the capillary point tending to become stopped. 



B. Tube prepared July loth, 1870. Solution of salts, as in preceding 

 experiments. Air expelled by boiling for ten minutes. Heated to 130° C. 

 Kept one year and two months. Examined September 12th, 1871. Vacuum 

 good. Nothing noticeable seen. 



C. Same solution, but with decidedly acid reaction. Prepared August 

 8th, 1870. Opened July 17th, 1871. Kept ten months and twenty-five days. 

 No trace of any organism ; many drops of liquid absolutely free from any 

 thing whatever. The lower end of this tube was a little too large, so that, 

 in spite of the upper end being closed, the liquid would drop out. It was 

 caught in a little glass vessel placed in the bell-jar, and drops were re- 

 moved as required by dipping the point of the tube in and touching the 

 glass slide. 



D. October 10th, 1870. A strong infusion was made by pouring warm 

 distilled water over finely shred turnips, and allowing to digest for some 

 time. The liquid was filtered twice through the finest Swedish paper, and 



* See ' Nature,' vol. ii. p. 177. 



