642 TRANSACTIONS OF SECTION Tf. 
a few seconds afterwards and recom nences a few seconds later, and gradually 
attains its previous form. The effest is obtained with larger doses of other 
members of the series. With tetra-ethyl-ammonium chloride very large doses 
(20 to 40 mg.) are required, and even these are not always effective. Instead 
gradual failure of the respiration may occur, This temporary paralysis of the 
respiration was ascribed by Tappeiner and Iodlbauer to stimulation of the fifth 
cranial nerve in the nose, and was said not to occur after cocainisation of the 
nasal mucous membrane. This I have been unable to corroborate. The effect 
is not obtained by injection of strong concentrations of tetra-methyl-ammonium 
chloride into the nasal cavity, and it is obtained in a modified form after division 
of both fifth nerves in the base of the skull. Moreover, the effect runs parallel 
to the diminution er loss of irritability of the diaphragm and fore-limb muscles 
to electrical stimulation of their nerves, and the doses of the various members 
of this series required to produce it are of the same order as those required to 
produce motor paralysis in the frog. It would seem therefore that the effect 
is partly, if not wholly, due to depression of the motor-nerve endings im tie 
respiratory muscles. 
14. The Pharmacological Action of Nitric Esters. By C. R. Marswatu. 
Pharmacologically the nitric esters act mainly on unstriped muscle-fibre and 
especially on that of the arterioles. Their chief effect is to cause a fall of blood- 
pressure owing to dilatation of the blood-vessels. That the action is peripheral 
may be shown by perfusion of the vessels of an isolated organ and in other ways. 
Doses producing distinct vaso-dilatation have no appreciable direct action on 
other organs of the body, but in men their administration is frequently followed 
by severe headache. The cause of this is unknown; but as it is not proportional 
to the degree of vaso-dilatation, it cannot, I think, be wholly ascribed to this 
action. set 
Large doses cause metheamoglobinemia, and if the dose be sufficiently large, 
death, in mammals, results from this cause. 
The nitric esters I have so far prepared and investigated are :— 
Methyl! nitrate. Dulcitol hexanitrate. 
Ethyl! nitrate. Dulcitol pentanitrate. 
n-Propyl nitrate. Sorbitol hexanitrate. 
iso-Propyl nitrate. 
n-Butyl nitrate. Arabinose tetranitrate. 
Glucose pentanitrate. 
Fructose pentanitrate. 
Rhamnose pentanitrate. 
Quercite pentanitrate. 
Saccharose octonitrate. 
Glycol dinitrate. 
Glycerol trinitrate. 
Glycerol dinitrate. 
Methyl-glycerol dinitrate, 
SHeshbon ay teense abe Tartaric acid dinitrate. 
Ethyl-tartaric acid dinitrate. 
Citric acid nitrate. 
Ethyl-citric acid nitrate. 
Lactic acid nitrate. 
Ethyl-lactic acid nitrate. 
Erythritol tetranitrate. 
Pentaerythritol tetranitrate. 
Arabitol pentanitrate. 
Mannitol hexanitrate. 
Mannitol pentanitrate. 
Dimethyl-mannitol tetranitrate. Cellulose nitrates. 
Tetramethyl-mannitol dinitrate. Starch nitrate. 
For the present purpose these substances may be divided into four groups : 
(i) The nitric esters of the monhydric alcohols. 
(ii) The nitric esters of the polyhydric alcohols and sugars. 
(iii) The nitric esters of starch and cellulose. 
(iv) The nitric esters of the acids and their alkyl compounds. 
The members of the last two groups do not produce the characteristic vaso- 
dilatation of most nitric esters—the nitric esters of starch and cellulose owing 
: 
