128 DEPARTMENT REPOKTS. 



thus induces a more rapid germination than the application of heat and 

 moisture alone. Humboldt employed a weak solution of chlorine which 

 possesses the power of decomposing water and thus setting oxygen at liberty ; 

 and diluted oxalic acid has been successfully used in the case of very old 

 seeds. Camphor has long been said to possess the property of hastening the 

 germination of seeds, and similar properties have been attributed to bromine, 

 chlorine, and iodine. M. Heckel has recently experimented with these sub- 

 stances, and the results go towards proving the correctness of this assertion. 

 Eadish seeds, simply moistened with pure water, germinated in eight days; 

 similar seeds, kept moist with iodine water, germinated in five days, with 

 bromine water in three days, and with chlorine water in two days. The 

 monobromide of camphor exhibited even greater quickening energy than 

 either of its constituents used separately, or than a simple mixture of 

 bromide and camphor, germination occurring after a mean interval of thirty- 

 six hours."* 



Experiments with the use of various substances as an aid to germination 

 were performed last year and this year. I select two which were conducted 

 with great care by my students. The first, which was published last year,f 

 was conducted by T. A. Stanley of the class of 1886, with results as 

 follows: 



Three weak solutions of chlorine and bromine were made, their strength 

 being represented by 1, 3-5, 1-5. There were also made some very weak lime 

 water and a very weak solution of oxalic acid. These various solutions, also 

 pute water, were put in separate bottles, into which different seeds were 

 placed to soak, some for eight hours and some for twenty-four. The seeds 

 were then placed on the surface of sand in small flower pots and covered with 

 glass to prevent too rapid evaporation. The pots were placed in boxes of 

 earth and kept moist by watering the earth about them. 



All this was done in the forcing house with no fire, and observations were 

 taken daily, morning, noon and night. As soon as a seed or seeds sprouted 

 record of the fact was made. These observations were continued until most 

 of the seeds had sprouted, but for sake of brevity the time when only the 

 first sprout appeared is here given. J 



In the table, the column at the left shows the kind of solution and its rela- 

 tive strength. The other columns contain the number of days elapsing from 

 the time the seeds were removed from the solutions to the time when the first 

 sprout was seen. 



The blanks indicate that no seeds sprouted. 



tion 



* Burbidge, Cultivated Plants, 33. 



+ Mich. Hort. Rep., 1886, 104. ^ ^, ^ .t. 



* At the time of experimenting, early in May, the weather was very nnfavorable for the germma- 

 on of seeds, and having no fire in the forcing house I had to do with what little heat nature gave. 



