HORTUS GRAMINEtJS WOBURNENSIS. 29S 



latter a glossy surface like that of ripened grain. The culms 

 at the time of flowering are also less hollow, and are more 

 tough and pliable than ripened straw, and therefore easier to 

 work into plait. From these facts it seems probable, that 

 the Italian straw is taken when the plants are in 

 flower. 



The green straw may be bleached by the process detailed 

 by the late Mr. Cobbett. The culms being selected and 

 placed in a convenient vessel, boiling water is poured over 

 them in quantity sufficient to cover the straw ; in this 

 they are to remain ten minutes : when thus scalded, they 

 are to be spread out on a grass- plat to bleach ; by turning 

 them once a day, the bleaching is generally effected in seven 

 or eight days. The bleaching, however, may be effected in 

 much less time ; especially if, instead of ten minutes, the 

 straw be allowed to remain in the scalding water from one to 

 two hours, and then spread on grass, regularly watered as 

 they become dry, turning them once a-day for two days, 

 after which the straw is washed clean from dust. It is then, 

 in a moist state, placed in a close vessel, and subjected to 

 the fumes of burning sulphur for two hours. This has been 

 found sufficient to bleach the straw in the most perfect 

 manner. Green straw immersed for ten minutes in a strong- 

 solution of acetic acid, and then subjected to the sulphure- 

 ous acid gas, are bleached perfectly white in half an hour. 

 Green culms, immersed for fifteen minutes in muriatic acid, 

 diluted with twenty times its measure of water, and then 

 spread on the grass, became in four days as perfectly 

 bleached as those which were scalded and bleached for 

 eight days on the grass. The texture of the straw was not 

 in the least injured, by these processes. The application of 

 the sulphureous acid gas to the moistened straw, even after 

 scalding and bleaching on the grass, had in every instance 

 the effect of greatly improving the colour. It is necessary 

 that the straw be moist during the application of the fumes 

 of sulphur, to obtain the greatest use of the gas ; for water 

 absorbs this gas with rapidity, and assists the action of the 

 gas, in destroying the colouring matter of the straw without 

 injury to its te.vture. The only apparatus necessary for the 



