16 



REPORT — 1855. 



The cause of this contrariety might naturally be sought for in the fact that 

 there was soil about the seeds in this year's experiment. In hopes of deter- 

 mining this point, and as the season was not too far advanced, the following 

 experiments were instituted. 



Two sets of the large, colourless, blue and yellow bell-glasses were taken. 

 The one set was placed over bricks in plates filled with water, and on the 

 bricks were simply laid, in each instance, twelve grains of wheat and eight 

 peas, previously weighed. They were placed in a sunny situation in the 

 garden, and the air was occasionally changed. This set, therefore, was ana- 

 logous to those described in the last Report. The other set was placed in a 

 sunny part of the garden over spots where the same number of grains of 

 wheat and of peas, also previously weighed, had been sown in the mould. 

 They were watered, and the air was changed from time to time. 



On May 26th, that is a few days after the commencement of the experi- 

 ment, the wheat and peas had begun to burst under all the six glasses. 

 Summer weather succeeded, warm sunshine and warm showers. 



The wheat on the bricks appeared to germinate first under the blue glass, 

 and it grew more quickly there, yet not so many had shown signs of life as 

 under the other glasses, and in about a month's time it was found that the 

 plants were growing about equally well under all the three shades, though 

 somewhat impeded by the luxuriant growth of the peas. On July 19th the 

 plants that had thriven were counted, measured, removed from the bricks, 

 allowed to dry in the air for twenty-four hours, and then weighed. 



The wheat that was sown in mould was found on May 30th to have grown 

 to the height of two inches under the colourless and the yellow shades, but 

 the plants were not so tall under the blue. Some of the wheat under the 

 yellow was remarkably fine. On July 19th, the following were the observed 

 results, the weight being taken as before : — 



It is worthy of remark, that whether with or without mould, the smallest 

 number of wheat-seeds have germinated under the influence of the chemical 

 ray ; yet they appear to have grown well under these circumstances up to a 

 certain point, but the plant seems to have required the luminous or the 

 calorific rays in order to profit much by the soil. 



The peas that were placed on the damp bricks were found on May 30th to 

 have put forth radicles of half an inch or upwards in length under all the glasses, 



