loomis] STUDY OF GERMINATION 203 



sometimes bedded in cold frames to furnish artificial heat to the 

 soil containing seeds which is placed on the manure. The man- 

 ure undergoes a fermenting process during which a remarkably 

 large quantity of heat is given off. As every one knows, certain 

 spots protected by buildings, or on the south side of walls and 

 hedges are chosen for early vegetables. For a similar reason 

 plots on the south side of hills are chosen. Crops in valleys are 

 usually many days earlier than the corresponding crop on the 

 neighboring hill. Even though the seeds are planted on the 

 same day, the extra amount of heat of the valley produces 

 quicker sprouting and subsequent growth. 



Although light is necessary for proper growth later, it clearly 

 has a retarding effect on sprouting. Very little attention is 

 given to the matter for the reason that in the planting of seeds 

 light is incidentally shut away. 



Seeds will not sproui without air. Arrange another chimney 

 with seeds and blotting paper and then close the top in the fol- 

 lowing manner: Secure from a dentist enough rubber sheeting 

 (rubber dam) to go over the top of the chimney tw r ice. Halve 

 the rubber, put mucilage around the top of the chimney and tie 

 one of the pieces of rubber over the top, winding twine many 

 times around to secure an air-tight joint. In order not to fail in 

 this matter, tie the other piece of rubber sheeting down over the 

 first tying it lower on the chimney, thus covering the first tying. 

 If you are painstaking in the matter, the joint will not only not 

 leak water, but air will not pass through it. It is practically 

 impossible to secure an air-tight joint with an ordinary cork, 

 otherwise it could be used in place of the rubber dam. As soon 

 as the mucilage is dry, invert the chimney and fill with water, 

 then displace the water with hydrogen gas. If a chemical labora- 

 tory is convenient you can secure apparatus for generating 

 hydrogen with little trouble. If you are not so situated, the fol- 

 lowing arrangement will answer very well. Into a small wide- 

 mouthed bottle (2- or 3 7 ounce) drop a number of ordinary nails, 

 add w r ater and to this add not over an ounce of sulphuric acid. 

 Bubbles of hydrogen gas will almost immediately begin to rise. 

 Keep all flames away from the escaping hydrogen. Lower the 

 bottle into a dish of water deep enough to cover the bottle an 

 inch or so. Now place a card over the bottom of the inverted 

 chimney of water and lower the chimney over the bottle from 



