182 Report S.A.A. Advaxckment of Science. 



Human 

 Horse 

 Cattle 

 Sheep 

 Pio 

 Dog- 

 Cat 



Hor.se 

 Cattle ... 

 Sheep 



Pig 



Dog 

 Cat 



aiul its ions Na+ Cl~. Normally the values of /i and A vary but 

 little, thus showing the accuracy with which the osmotic pressure is 

 regulated. In pathological cases, however, the \ariations have a wide 

 range, and in human medicine these methods have given ver}' valuable 

 diagnostical and prognostical indications, especialh^ in diseases of the 

 heart and kidneys. 



We have applied both methods to study the alterations in salt 

 concentration of the serum in piroplasmosis and horse-sickness, and in 

 order to follow the course of the disease the examinations were made 

 daily for about a month : — 



In severe cases of piro])lasnwsis the A of serum increases first, 

 and then falls below the normal Aalue. A urine is also found sub- 

 normal. This latter changes Avithin wider limits than the depression 

 of serum, and as a rule is greater. The A of urine decreases and 

 increases according to the specific gravity. The electrical conductivity 

 of serum is also found lower than normal, and it decreases already 

 during the incubation time before the tempei'ature reaction ensues. 

 Sometimes a precipitation of A is observed on the first day after 

 injection. 



The results of the freezing-points and condu(;ti\ ity examinations 

 demonstrate that the absolute osmotical concentration in serum and 

 urine decrease during this disease, and that the ion concentration 

 is especially reduced. The rise of'- A serum in a few cases has to 

 be attributed to an increase of the concentration of non-electrolytes, 

 since the conductivity was not rising, but falling, probably owing to 

 the reduction of dissociation by the non-electrolytes. Tn the other 

 horses the curves of A ""d A were not always parallel. Of course, if 

 they are corresponding, the concentration of the ions only varies, if A 

 increases and A decreases the non-electrolytes have increased to a great 

 extent ; if A i"emains constant and A becomes lower the concentration 



