250 



Mr. r. Gr. Jackson and Dr. V. Harley. 



On instituting a comparison between the results now communicated 

 and those formerly published for the triplet of zinc double sulphates, it 

 is found that the replacement of sulphur by selenium is generally 

 accompanied by a change in the morphological and physical constants 

 similar to that which accompanies the replacement of one alkali metal 

 by another of higher atomic weight. The changes due to the latter 

 chemical change are often smaller in the selenate series than in the 

 sulphate series, the greater weight of the initial molecule appearing to 

 offer greater resistance to change. The intermediate character of the 

 constants of the rubidium salt is, however, the invariable rule in both 

 cases. 



"An Experimental Inquiry into Scurvy."* By Feederick 

 Jackson and Vaughan Harley, M.D. Communicated by 

 Lord Lister, P.E.S. Eeceived February 15, — Eead March 1, 

 1900. 



(From the Department of Pathological Chemistry, University College, London.) 



The view that scurvy is caused by the want of fresh vegetables or 

 lime juice, which has been the teaching of physicians and scientists in 

 past years, would appear to require modification. 



In the early part of this century, through the efforts largely of 

 Lind, the better feeding of sailors led to the gradual disappearance of 

 scurvy in the naval service, and from this and other observed facts it 

 was conceived that the disease developed whenever individuals did not 

 receive a sufficient quantity of fresh vegetables, or some substitute,, 

 such as lime juice, in the diet. 



Garrod held that the cause of scurvy was a deficiency of potassium 

 salts, while others believed the essential factor to be the absence of 

 organic salts, which are present in fruits and vegetables. 



Ealfe believed the absence from the food of malates, citrates, and 

 lactates reduced the alkalinity of the blood, and thus was the cause of 

 scurvy. It was proved, however, by analysis that the alkalinity of 

 the blood was not diminished, and the majority of evidence showed 

 no diminution in the quantity of potash salts in the scorbutic blood, so 

 that these explanations had to be abandoned. 



Neale, in an article on " Scurvy in the Arctic Eegions," published 

 in the 'Practitioner,' 1896, stated that "scurvy is a disease due to 

 want of proper ventilation and want of proper blood nourishment ; in 

 fact, scurvy begins with anaemia, and its great antidote is fresh blood." 

 He consequently did not consider that fresh vegetables were of such 



* Towards the expenses of this research a grant was received from the Koyal 

 Society. 



