15 
so many of the disturbing factors had been eliminated. It was 
naturally impossible to make allowances for the yearly variation 
* which was known to take place, and therefore the argument for a 
uniform product based upon these facts alone falls to the ground. 
Jacquet, who pointed out in his paper these advantages of the 
dialysates, made a number of physiological tests on the dialysates 
of digitalis and Adonis vernalis. He employed frogs (R. esculeuta 
and temporaria) with exposed hearts, injecting the drug into the 
lymph sacs and noting the length of time before death. He also 
studied their action upon the blood pressure and heart rate in rabbits 
and noted the toxic dose. 
By a comparison of the results obtained in this way with those 
he obtained under similar conditions using digitoxin and digitalium 
verum he estimated the dose of the dialysates which it would be 
proper to employ in man, it being possible to do this as the thera- 
peutic dose of the active principles for man was already known. 
It appears that Jacquet approached more nearly to physiological 
standardization than any of his predecessors, as he points out the 
advantage of the dialysates in affording an exact dosage, but it 
was not until his second paper, a which appeared in December, 1898, 
that he seems really to have adopted physiological standardization. 
As stated above, he believed that a uniform preparation had been 
obtained by eliminating so many factors which go to make the 
great variations which are found in the ordinary galenical prepara- 
tions; but as he stated then, he was unable to avoid the yearly 
variation in plants. This was evidently quite a large factor, as, 
examining the 1896 specimen, he was able to isolate 0.16 per cent 
of the active constituent, while in the 1897 preparation there was 
only 0.096 per cent. This variation he ascribed to the fact that 
the weather was unsettled at the time of gathering the leaves, and 
on that account the plants contained an unusually large amount of 
water. He therefore compared the two dialysates by physiological 
methods and found the same relative differences, for while ten drops 
of the 1896 specimen produced systolic standstill in frogs, it took 
twenty drops of the 1897 preparation. Likewise, it took double the 
amount of the 1897 preparation to kill rabbits. 
Recognizing at this time the yearly variation, which is apparently 
of a good deal of importance, he suggested that either a yearly 
change of dose would be necessary or an adjustment of the solution 
by evaporation or dilution as might be necessary, so as to give a 
uniform product. The latter course he thought preferable. This 
paper, in which he really adopted the physiological method of 
standardization, was, however, preceded by one by Houghton 
which appeared in America in October, 1898. 
a A. Jacquet, Cor.-Bl. f. schweizer Aerzte, 1898, XXVIII, 745. 
