212 J. M. Merrick, Jr., on Inhalation of Nitroglycerine. 
modify the flow of water in a natural channel, as practically 
beyond their reach. Hydraulic formule must, accordingly, 
from the nature of the case, be to a great extent empirical; and 
the highest degree of theoretic plausibility which such a formula 
may bring to recommend it, can at best only serve as an encour- 
agement to us to try it, in order that we may ascertain how far 
it may truly represent nature. The experience gathered in such 
past trials has not, however, been of a nature to render the 
encouragement a very solid ground of hope for a favorable 
result. 
The test then of actual trial is that to which we must bring 
at last all theorems in hydraulics; and our judgments of their 
merits will be regulated S the manner in which they stand this 
test. This is a principle which the authors of the report before 
us seem to have fully recognized; and the thoroughness with 
which they have applied it to their own formule is without any 
past example in the history of such investigations. We thin 
them, therefore, fully justified in the modest claim with which 
they conclude this part of their labor, viz., that these formule 
are “entitled to the confidence of practical men.” 
Art. XIX.—On Inhalation of Nitroglycerine ; by JouN M. 
MERRICK, Jr. 
Various experiments have been made by different observers’ 
upon the action of nitroglycerine or glonoine upon the animal 
economy—the nitroglycerine, or its solution in alcohol, bem 
administered by dropping it upon the tongue—the effects whi 
have been noticed being generally acceleration of the pulse, 
headache and prostration, and in peculiarly susceptible persons, 
these symptoms greatly aggravated. 
These experiments, though somewhat contradictory, are very 
logical point of view, 
n preparing a quantity of nitroglycerine in 1859, I met with 
an accident, the result of which exhibits in a very marked an( 
it, especially when mixed with a volatile and inflammable so! 
vent, as alcohol or ether. acl 
* Vide Braithwaite’s Retrospect of Practical Medicine, part xxxvii, p. 294- 
