EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 245 



fringed margins, and as it were granular. They are present in the 

 blood of all animals, and may be seen circulating in the blood within 

 the vessels ; their number is greater than might be imagined ; they 

 are burst by water, dissolved by ammonia, and shrivelled by acetic acid ; 

 they appear formed of three or four solid granules or corpuscles, en- 

 closed in a vesicle. 



These corpuscles measure only -g^th of a millimeter in diameter, and 

 are exactly similar to chyle corpuscles. 



Neither the mode of formation nor destination of the blood-globules 

 has been hitherto known. The result of M. Donne's researches on this 

 subject is as follows : 



The blood -globules are not all identical, nor in the same stage of for- 

 mation ; they do not all resist the action of chemical re-agents in the 

 same manner ; and the difference of their properties indicates that they 

 are not all arrived at the same degree of development. 



The corpuscles are the product of the chyle constantly poured into 

 the blood ; these corpuscles unite together by three or four, and become 

 enveloped in an albuminous covering whilst circulating with the blood : 

 in this manner they constitute the white globules. 



When once these white globules are formed, they gradually change 

 their shape ; they become flattened, coloured, and the internal granular 

 matter becomes homogeneous or dissolved ; ultimately they are converted 

 into the proper blood or red globules. 



The red blood- globules themselves have only a limited existence. 

 They dissolve in the blood at the expiration of a certain time, consti- 

 tuting the liquor sanguinis properly so called. Certain substances are 

 susceptible of an immediate change into blood-globules, when mixed 

 directly with the blood. Milk, which, from its organic constitution, as 

 well as from its principal elements and physiological properties, has 

 the greatest analogy to the blood, is best fitted to demonstrate this 

 change. 



Injections of milk into the veins of animals in certain proportions, 

 produce no ill effect, and the nature of its globules allows us to follow 

 and to recognize them everywhere. 



Besides, observation proves, that these globules injected into the 

 vessels are immediately changed into blood- globules by the same mecha- 

 nism which causes chyle corpuscles to become white globules, and these 

 latter to be transformed into red globules. 



The spleen appears specially destined to effect this change ; for it is 

 in this organ more particularly that we find the greatest number of 

 white globules, in every state of formation. 



The examination of the circulation in the most vascular organs, does 

 not show that the blood-globules leave their vessels for the purpose of 

 combining with other organs, or with organic elements ; but the fluid 

 part of the blood passes through the vascular parietes, and constitutes 

 probably the essential organizing medium. 



In conclusion, young animals, when brought up on other substances 

 than milk, are less perfectly nourished than those which are left com- 

 pletely to nature; and the influence of an inappropriate nourishment, may 

 go far towards altering the shape and nature of the blood-globules. 



