150 REPORT 1871. 



hours. The temperature of the body undergoes considerable change, falling, 

 in the pigeon, full five degrees Fahi-euheit, and remaining so reduced that a 

 period of eight and even nine hours is required for its complete restoration 

 to the natural standard. On frogs the effect of metachloral is equally marked. 

 A frog -weighing ten drachms is fairly narcotized in thirty minutes by a dose 

 of a quarter of a grain, the insensibility continuing manj' hours and closely 

 simulating death. During the period of deep insensibility the muscles re- 

 main in the most extreme state of flaccidity, but do not fail to respond to 

 the galvanic stimulus. 



To rabbits comparatively larger doses of metachloral may be administered 

 by the mouth -n-ithoat exciting any eflect whatever. To a large rabbit weighing 

 eight pounds, ten grains may be given with absolute freedom from symptoms 

 of narcotism ; but when the dose is increased to twenty grains a very distinct 

 effect is produced. About one hour following upon the administration the 

 animal sinks into sleep precisely as if he had taken chloral hydi-atc, and 

 passes through all the stages of narcotism and recovery in the same way. 



The action of metachloral is fidl of interest in a physiological point of 

 view, and goes far, I think, to sustain Liebreich's original view of the action 

 of chloral hydrate, \'iz. that the narcotism produced by it is due to the action of 

 chloroform liberated within the body. On this view metachloral is first 

 changed in the body, under the influence of alkali, into the soluble condi- 

 tion, after which it passes into the hydrate, and then into alkaline formate 

 and chloroform. It is thus slower tliau the hydrate and slower than the 

 anhydrous chloral in its action, but in the end the effects from it are the same. 

 Metachloral admits of being employed mcdicinaUy ; it may be combined 

 with morphia, quinine, and other alkaloids, and wUl, I think, be foimd to 

 possess many useful medicinal qualities. 



Beomal Hyde ate. 



"WTien bromine is made to act upon chlorine, a substance called brom-al is 

 the product. It is an oily substance like chloral, and when acted upon by 

 alkalies is decomposed into formiate of the alkali employed, and into bromo- 

 form, the analogue in the bromine of chloroform in the chlorine series. The 

 composition of bromal is C, HBrjO. When it is treated with water a crys- 

 talline substance, bromal hydrate, is produced. The composition of bromal 

 hydrate is C^ H lii\ 2H, ; it is the analogue in the bromine of the chloral 

 hydrate in the chlorine series. Eromal hydrate has an odour somewhat like 

 chloral liydi'ate ; its crystals are verj- soluble in water, and it may be ad- 

 ministered in solution by the mouth or by hypodermic injection. 



Verj' soon after the discovery of the action of chloral hydi-ate I commenced 

 a research on the physiological properties of the bromal hydrate. Two other 

 observers also moved in the same path, and have preceded me in recording 

 what they had observed. One of these is Dr. Steinann, of Berlin, the other 

 Dr. John DougaU, of Glasgow. In theu" researches nearly the same class of 

 inquiries were instituted as in my own, the same animals were subjected to 

 observation, and practically the same results were obtained. 



In order to i:)roduce marked cflects from bromal hydrate, much smaller 

 doses are required than of the corresponding chloral compound ; five grains 

 of the former are equivalent to ten of the latter. After an ctncient dose the 

 symptoms produced resemble in many respects the symptoms that foUow 

 chloral; i. e. there is great muscular prostration and a kind of narcotism, at- 

 tended, however, with very slight insensibility, except in cases in which the 

 dose has been dangerously large. In extreme cases only is there really deep 



