586 SCIENCE PROGRESS 



When destruction might be supposed to be complete the 

 dog was killed and an extract of the remaining portions of the 

 gland prepared — that is to say, an extract of the islands of 

 Langerhans. 



This extract was tested on a second dog which had previously 

 been deprived of its pancreas and which was, in consequence, 

 suffering from diabetes mellitus. The sugar swiftly disappeared 

 from both blood and urine and the dog became much better 

 in every way. 



A great deal of work has been done since this early experi- 

 ment. It has, however, only served to confirm the original 

 observations. Happily a method of alcoholic extraction has 

 been devised which obviates the necessity of repeating the 

 elaborate technique of the first attempts. The " insulin " can 

 be recovered from ordinary " slaughter-house " glands. 



The work was performed in Prof. McLeod's laboratory and 

 under his general supervision. In order to protect the public 

 a patent was taken out, and the British rights in this matter 

 have been presented to the Medical Research Council. This 

 body sent Dr. H. H. Dale to Toronto to investigate, and 

 he is now working out improved methods of extraction of the 

 anti-diabetic internal secretion. These, it is stated, are already 

 so far developed as to promise a high insulin yield per pancreas 

 — a matter of very great importance. 



The new " insulin " has been tried in many cases of diabetes, 

 with marked success. After a single injection sugar may so 

 far disappear from the blood as to cause symptoms of acute 

 sugar-want, and therefore great care in administration is 

 essential. In cases of acidosis the extract " works like a charm," 

 and it is also very successful where young subjects are con- 

 cerned. Its disadvantages, at present, are that it must be 

 injected and that certain difficulties of dosage are apt to 

 present themselves. Treatment must, of course, be continued 

 indefinitely. If it is stopped the patients, who have put on 

 flesh and improved in spirits, quickly relapse to their former 

 condition. 



It is as yet impossible to form anything like a final estimate 

 of this work. If, however, the early promise is fulfilled, medicine 

 will have acquired a new weapon of the most important kind. 

 For what thyroid treatment has done for myxoedema and 

 cretinism, insulin treatment bids fair to achieve for diabetes. 



The third annual Report of the Medical Research Council 

 has been issued. It treats of a wide variety of subjects, most 

 of which have already been mentioned in these columns. 

 Special reference is made to Dr. Harriette Chick's discovery of 



