Chap. VII. PHOSPHATE OF AMMONIA. 161 



Four leaves were immersed as before, each in thirty minims 

 of a solution of one part to 328,125 of water (1 gr. to 750 oz.). 

 Each leaf thus received y^^oo ^f a grain (-0054 mg.) of the salt ; 

 and all four were greatly inflected. 



(1) After 1 hr. all the outer tentacles but one inflected, and 

 the blade greatly so ; after 7 hrs. began to re-expand. 



(2) After 1 hr. all the outer tentacles but eight inflected; 

 after 12 hrs. all re-expanded. 



(3) After 1 hr. much inflection ; after 2 hrs. 30 m. all the ten- 

 tacles but thirty-six inflected ; after 6 hrs. all but twenty-two 

 inflected ; after 12 hrs. partly re-expanded. 



(4) After 1 hr. all the tentacles but thirty-two inflected; after 

 2 hrs. 30 m. all but twenty-one inflected ; after 6 hrs. almost 

 re-expanded. 



Of the four corresponding leaves in water : — 



(1) After 1 hr. forty-five tentacles inflected ; but after 7 hrs. 

 so many had re-expanded that only ten remained much inflected. 



(2) After 1 hr. seven tentacles inflected; these were almost 

 re -expanded in G hrs. 



(3) and (4) Not affected, except that, as usual, after 11 hrs. 

 the short tentacles on the borders of the disc formed a ring. 



There can, therefore, be no doubt about the efiicicncy of the 

 above solution ; and it follows as before that each gland of No. 1 

 could have absorbed only g^i^opQ of a grain (0000268 mg.) 

 and of No. 2 only aioiooo of a grain (-0000263 mg.) of the 

 phosphate. 



Seven leaves were immersed, each in thirty minims of a 

 solution of one part to 437,500 of water (1 gr. to ICOO oz.). 

 Each leaf thus received tq^oo of a grain (-00105 mg.). The day 

 was warm, and the leaves were very. fine, so that all circum- 

 stances were favourable. 



(1) After 30 m. all the outer tentacles except five inflected, 

 and most of them closely ; after 1 hr. blade slightly inflected ; 

 after 9 hrs. 30 m. began to re-expand. 



(2) After 33 m. all the outer tentacles but twenty-five in- 

 flected, and blade shghtly so ; after 1 hr. 30 m. blade strongly 

 inflected and remained so for 21 hrs. ; but some of the tentacles 

 had then re-expanded. 



(3) After 1 hr. all but twelve tentacles inflected ; after 2 hrs. 

 80 m. all but nine inflected ; and of the inflected tentacles all 

 excepting four closely; blade slightly inflected. After 8 hrs. 

 blade quite doubled up, and now all the tentacles excepting 



