148 REPORT ISri. 



Anhtdrotts Chloral. 



The hydrate of chloral, of which I have treated above, is made from 

 another substance, called anhydrous chloral, by the addition to the latter of a 

 certain proportion of simple water. Anhydrous chloral was discovered 

 by Liebig in 1832, and is formed by the process of passing chlorine through 

 absoMe alcohol. It is a colourless oily fluid, of specific gravity 1502, at 

 64° Pahr. It boils at 93° Cent. (199° Fahr.); its composition is C.HClj 0, and 

 its vapour-density, taking hydrogen as unity, is 73. It dissolves in ether, 

 alcohol, and hydride of amyl. 



The vapour of anhydrous chloral is irritating and painful to an extreme 

 degree when it is inhaled, and the substance has consequently not attracted 

 attention as a subject for physiological study. Having, however, a pure 

 specimen of it prepared by Dr. Versmann, I thought it was worth while to 

 make a research with it. The results have proved worthy of the trouble ; in 

 fact I have rarely derived from so simple an investigation so rich a practical 

 result. It would be inferred a priori that anhydrous chloral in the liquid 

 state would be, like its vapour, a powerful irritant to the skin and mucous 

 membrane. I soon found, however, that this was not the fact, that I could 

 apply the fluid freely to my ovm. skin and to the tongue without injury, and 

 that the caustic action is extremely mild, even when the substance is applied 

 to a moist surface. If a quarter grain of it (anhydrous chloral) be placed 

 upon the skin of the frog in a dry atmosphere, there is a rather quick ab- 

 sorption, followed by the formation of a white film of the hydrate of chloral 

 beneath the skin, which film soon disappears by absorption, the symptoms 

 following the absorption being the specific narcotic symptoms of chloral 

 hydrate. The animal soon falls into a deep sleep with complete muscular 

 exhaustion. 



If in higher animals, birds and rabbits, anhydrous chloral be injected sub- 

 cutaneously, the same phenomena are indicated, the quantities for producing 

 the specific effects being the same as are required for the hydrate. 



It is clear from these observations that anhydrous chloral, when brought 

 into contact with the exposed surfaces of the^body, abstracts water from the 

 part with which it is in contact, becomes converted into the hydrate, and is 

 directly absorbed into the body, producing tlie same symptoms as the pre- 

 pared hydrate produces when it is introduced into the organism. 



As anhydrous chloral is soluble in amyl hydride, ether, and many other 

 volatile fluids, I tried whether any of it coiild be carried over with the vapour 

 of amyl hydride, and whether, if it were administered in this way, it would 

 produce prolonged narcotism by being transformed into the hydrate in the 

 lungs and taken up into the blood. 



The result of the experiment was to show that in frogs, guineapigs, and 

 pigeons general narcotism can be so induced, and that the narcotism is pro- 

 longed far beyond what follows from the simple inhalation of amyl hydride. 

 But I observed that when the solution used contained so little as twenty 

 minims of anhydrous chloral to an ounce of the hydride, the vapour given ofl:" 

 was irritating to breathe ; and when I breathed it myself I found it caused dry- 

 ness of the throat and a sense of constriction, which lasted several minutes. A 

 weaker solution than that named is too slow in its action, and I therefore can 

 hardly at this moment recommend that anhydrous chloral should be ad- 

 ministered by inhalation. It is possible, nevertheless, that in course of time 

 the agent may be found serviceable when administered in the manner de- 

 scribed. It is probable that much smaller quantities, administered for a much 



