PHYSIOLOGY. 



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plicants for licenses, in such States as have 

 pharmacy laws, boards of pharmacy have been 

 appointed from among the best representatives 

 of the profession, to examine candidates and 

 grant diplomas allowing them to practice. 

 Many of the States have pharmacy laws, but 

 they differ very greatly, and an effort is being 

 made to establish uniformity throughout the 

 country. Certain portions of the Union are 

 still without any laws on this subject. 



Literature. The " Pharmacopoeia of the Uni- 

 ted States" is the recognized official man- 

 ual of the pharmacists. This work is revised 

 and issued every ten years by the authority 

 of a National Convention held at Washington, 

 and composed of delegates from the medical 

 and pharmaceutical colleges. Although not 

 authorized by the Government, it is accepted 

 as the authority by which legal disputes rel- 

 ative to drugs shall be settled. The present 

 edition is the sixth decennial revision, of 1880, 

 and was published in 1882. The " Dispensatory 

 of the United States," edited by H. 0. Wood, 

 Joseph P. Remington, and S. P. Sadtler, oc- 

 cupies the position of commentary to the 

 Pharmacopoeia. It gives very full descrip- 

 tions of the articles mentioned in the " United 

 States Pharmacopoeia," and also includes 

 those given in the " British Pharmacopoeia." 

 It further embraces extensive and comprehen- 

 sive information in regard to other drugs and 

 chemicals used in pharmacy and medicine, that 

 are not officinal. A revised edition appeared 

 in 1883. Other important works are: Par- 

 rish's "Treatise on Pharmacy" (Philadelphia, 

 1883), and "Lectures on Practical Pharmacy," 

 by Barnard S. Procter (Philadelphia, 1883). 

 Among the journals devoted to pharmacy are 

 the "American Journal of Pharmacy," "The 

 Druggist's Circular," the " American Drug- 

 gist," and the " Weekly Drug News." 



Practical chemistry and experimental thera- 

 peutics are continually adding new drugs and 

 preparations to the resources of pharmacy. 



PHYSIOLOGY. The Heart. Dr. W. H. Gaskell, 

 F. R. S., of Cambridge, has published (" Jour- 

 nal of Physiology ") an account of experiments 

 upon the innervation of the heart. Previous ex- 

 periments in this line having been made with 

 the heart of the frog, he selected the heart of 

 the tortoise, so as to secure corresponding ob- 

 servations with other animal types for com- 

 parison. His investigations bore : 1. On the 

 spontaneous rhythm of the different parts of 

 the heart and of the heart as a whole; 2. On 

 the sequence of the contractions of the differ- 

 ent heart-cavities; 3. On the action of the 

 cardiac nerves ; 4. On the action of atropine and 

 muscarine. Before the nerves of the heart and 

 the ganglion-cells were known, the beat of 

 the heart was attributed to the direct stimu- 

 lating action of the blood on the cardiac mus- 

 cle. The. discovery of the cardiac ganglia and 

 of their situation in the sinus, where the origin 

 of the rhythmic beat was located, led to the hy- 

 pothesis that they played the chief part in the 



causation of the beat, although they were at 

 the same time recognized as appendages to the 

 nerves, and not separate, independent struct- 

 ures ; and experiments were referred to which 

 were thought to afford positive proof of the 

 preponderating influence of the ganglion -cells 

 in the causation of rhythm, and other experi- 

 ments were thought to indicate the mode in 

 which they acted. When, however, it became 

 known that a constant stimulus, whether elec- 

 trical, chemical, or mechanical, applied to the 

 muscular tissue at the apex, could cause that 

 muscle to beat rhythmically, even though no 

 nerve-cells were to be found in it, the question 

 arose, Are these motor centers really similar 

 to those of the respiratory center, or is it not 

 more likely that they supply a constant stim- 

 ulus to the muscle, and that it is the property 

 of the cardiac muscle to produce rhythmical re- 

 sults from that continually acting stimulation ? 

 On either view, certain ganglia are supposed 

 to possess motor functions, upon which the 

 heart-beat ultimately depends, and the cardiac 

 muscle itself is not supposed to possess any 

 power of automatic rhythm, but merely to 

 contract rhythmically upon the application of 

 a suitable external stimulus. The results of 

 Dr. Gaskell's experiments are adverse to this 

 hypothesis. In their light, the heart is con- 

 ceived as a specially modified portion of the 

 vascular system ; as a piece of artery or vein, 

 the muscular walls of which have developed 

 in a special manner. The peculiarities of the 

 cardiac muscle arise from its structural, posi- 

 tion, intermediate between unstriped and stri- 

 ated muscular fiber. Muscular tissues exhibit 

 three different modes of responding to stimu- 

 lation " tonic," "rhythmical," and "rapid" 

 contraction according to their structure. The 

 difference between them is clearly shown in a 

 comparison of the tetanizing action of a strong 

 interrupted current upon a strip of muscle from 

 the bladder of the tortoise, and from the heart 

 of the tortoise, and with the ordinary tetanus 

 curve of the frog's gastrocnemius. The un- 

 striped muscle of the bladder contracts slowly 

 after a long latent period, with steadily increas- 

 ing force during and even after the cessation 

 of the tetanizing current, and the strip returns 

 slowly to its original length. This represents 

 a prolonged tonic contraction. The striated 

 muscle gives the curve of tetanus, consisting of 

 the superposition of a series of rapid contrac- 

 tions. And the cardiac strip gives a curve 

 which is intermediate between the two, and 

 may be described as a long-continued tonic 

 contraction upon which are superimposed a 

 number of rapid contractions that never suc- 

 ceed one another so quickly as to fuse together. 

 The cardiac muscle, then, when tetanized gives 

 a tetanus of tonicity in virtue, of its relation- 

 ship to unstriped muscle, and at the same 

 time a series of rapid contractions in conse- 

 quence of its affinity to striated muscle. When 

 the vitality of the tissue is impaired, the car- 

 diac muscle loses its power of rapid contrac- 



